deleted file mode 100644
--- a/layout/base/AccessibleCaretLogger.cpp
+++ /dev/null
@@ -1,23 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "AccessibleCaretLogger.h"
-
-namespace mozilla {
-
-PRLogModuleInfo*
-GetAccessibleCaretLog()
-{
-  static PRLogModuleInfo* log = nullptr;
-
-  if (!log) {
-    log = PR_NewLogModule("AccessibleCaret");
-  }
-
-  return log;
-}
-
-} // namespace mozilla

--- a/layout/base/AccessibleCaretLogger.h
+++ b/layout/base/AccessibleCaretLogger.h
@@ -6,22 +6,22 @@
 
 #ifndef AccessibleCaretLog_h
 #define AccessibleCaretLog_h
 
 #include "mozilla/Logging.h"
 
 namespace mozilla {
 
-PRLogModuleInfo* GetAccessibleCaretLog();
+static LazyLogModule sAccessibleCaretLog("AccessibleCaret");
 
 #ifndef AC_LOG_BASE
-#define AC_LOG_BASE(...) MOZ_LOG(GetAccessibleCaretLog(), mozilla::LogLevel::Debug, (__VA_ARGS__));
+#define AC_LOG_BASE(...) MOZ_LOG(sAccessibleCaretLog, mozilla::LogLevel::Debug, (__VA_ARGS__));
 #endif
 
 #ifndef AC_LOGV_BASE
 #define AC_LOGV_BASE(...)                                                      \
-  MOZ_LOG(GetAccessibleCaretLog(), LogLevel::Verbose, (__VA_ARGS__));
+  MOZ_LOG(sAccessibleCaretLog, LogLevel::Verbose, (__VA_ARGS__));
 #endif
 
 } // namespace mozilla
 
 #endif // AccessibleCaretLog_h

--- a/layout/base/LayoutLogging.cpp
+++ b/layout/base/LayoutLogging.cpp
@@ -3,40 +3,30 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 // Chromium headers must come before Mozilla headers.
 #include "base/process_util.h"
 
 #include "LayoutLogging.h"
 
-PRLogModuleInfo* GetLayoutLog()
-{
-  static PRLogModuleInfo* log = nullptr;
-  if (!log) {
-    log = PR_NewLogModule("layout");
-  }
-
-  return log;
-}
-
 namespace mozilla {
 namespace detail {
 
 void LayoutLogWarning(const char* aStr, const char* aExpr,
                       const char* aFile, int32_t aLine)
 {
   if (aExpr) {
-    MOZ_LOG(GetLayoutLog(),
+    MOZ_LOG(sLayoutLog,
             mozilla::LogLevel::Warning,
             ("[%d] WARNING: %s: '%s', file %s, line %d",
              base::GetCurrentProcId(),
              aStr, aExpr, aFile, aLine));
   } else {
-    MOZ_LOG(GetLayoutLog(),
+    MOZ_LOG(sLayoutLog,
             mozilla::LogLevel::Warning,
             ("[%d] WARNING: %s: file %s, line %d",
              base::GetCurrentProcId(),
              aStr, aFile, aLine));
   }
 }
 
 } // namespace detail

--- a/layout/base/LayoutLogging.h
+++ b/layout/base/LayoutLogging.h
@@ -6,28 +6,28 @@
 #ifndef LayoutLogging_h
 #define LayoutLogging_h
 
 #include "mozilla/Logging.h"
 
 /**
  * Retrieves the log module to use for layout logging.
  */
-PRLogModuleInfo* GetLayoutLog();
+static mozilla::LazyLogModule sLayoutLog("layout");
 
 /**
  * Use the layout log to warn if a given condition is false.
  *
  * This is only enabled in debug builds and the logging is only displayed if
  * the environmental variable NSPR_LOG_MODULES includes "layout:2" (or higher).
  */
 #ifdef DEBUG
 #define LAYOUT_WARN_IF_FALSE(_cond, _msg)                                  \
   PR_BEGIN_MACRO                                                           \
-    if (MOZ_LOG_TEST(GetLayoutLog(), mozilla::LogLevel::Warning) &&        \
+    if (MOZ_LOG_TEST(sLayoutLog, mozilla::LogLevel::Warning) &&        \
         !(_cond)) {                                                        \
       mozilla::detail::LayoutLogWarning(_msg, #_cond, __FILE__, __LINE__); \
     }                                                                      \
   PR_END_MACRO
 #else
 #define LAYOUT_WARN_IF_FALSE(_cond, _msg) \
   PR_BEGIN_MACRO                          \
   PR_END_MACRO
@@ -37,17 +37,17 @@ PRLogModuleInfo* GetLayoutLog();
  * Use the layout log to emit a warning with the same format as NS_WARNING.
  *
  * This is only enabled in debug builds and the logging is only displayed if
  * the environmental variable NSPR_LOG_MODULES includes "layout:2" (or higher).
  */
 #ifdef DEBUG
 #define LAYOUT_WARNING(_msg)                                                \
   PR_BEGIN_MACRO                                                            \
-    if (MOZ_LOG_TEST(GetLayoutLog(), mozilla::LogLevel::Warning)) {         \
+    if (MOZ_LOG_TEST(sLayoutLog, mozilla::LogLevel::Warning)) {         \
       mozilla::detail::LayoutLogWarning(_msg, nullptr, __FILE__, __LINE__); \
     }                                                                       \
   PR_END_MACRO
 #else
 #define LAYOUT_WARNING(_msg) \
   PR_BEGIN_MACRO             \
   PR_END_MACRO
 #endif

--- a/layout/base/SelectionCarets.cpp
+++ b/layout/base/SelectionCarets.cpp
@@ -35,18 +35,18 @@
 #include "mozilla/TouchEvents.h"
 #include "Layers.h"
 #include "TouchCaret.h"
 #include "nsFrameSelection.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
 
-static PRLogModuleInfo* gSelectionCaretsLog;
 static const char* kSelectionCaretsLogModuleName = "SelectionCarets";
+static mozilla::LazyLogModule gSelectionCaretsLog(kSelectionCaretsLogModuleName);
 
 // To enable all the SELECTIONCARETS_LOG print statements, set the environment
 // variable NSPR_LOG_MODULES=SelectionCarets:5
 #define SELECTIONCARETS_LOG(message, ...)                                      \
   MOZ_LOG(gSelectionCaretsLog, LogLevel::Debug,                                    \
          ("SelectionCarets (%p): %s:%d : " message "\n", this, __FUNCTION__,   \
           __LINE__, ##__VA_ARGS__));
 
@@ -80,20 +80,16 @@ SelectionCarets::SelectionCarets(nsIPres
   , mEndCaretVisible(false)
   , mStartCaretVisible(false)
   , mSelectionVisibleInScrollFrames(true)
   , mVisible(false)
   , mActionBarViewID(0)
 {
   MOZ_ASSERT(NS_IsMainThread());
 
-  if (!gSelectionCaretsLog) {
-    gSelectionCaretsLog = PR_NewLogModule(kSelectionCaretsLogModuleName);
-  }
-
   SELECTIONCARETS_LOG("Constructor, PresShell=%p", mPresShell);
 
   static bool addedPref = false;
   if (!addedPref) {
     Preferences::AddIntVarCache(&sSelectionCaretsInflateSize,
                                 "selectioncaret.inflatesize.threshold");
     Preferences::AddBoolVarCache(&sSelectionCaretDetectsLongTap,
                                  "selectioncaret.detects.longtap", true);

--- a/layout/base/TouchCaret.cpp
+++ b/layout/base/TouchCaret.cpp
@@ -31,18 +31,18 @@
 #include "nsView.h"
 #include "mozilla/dom/SelectionStateChangedEvent.h"
 #include "mozilla/dom/CustomEvent.h"
 #include "mozilla/BasicEvents.h"
 #include "mozilla/Preferences.h"
 
 using namespace mozilla;
 
-static PRLogModuleInfo* gTouchCaretLog;
 static const char* kTouchCaretLogModuleName = "TouchCaret";
+static mozilla::LazyLogModule gTouchCaretLog(kTouchCaretLogModuleName);
 
 // To enable all the TOUCHCARET_LOG print statements, set the environment
 // variable NSPR_LOG_MODULES=TouchCaret:5
 #define TOUCHCARET_LOG(message, ...)                                           \
   MOZ_LOG(gTouchCaretLog, LogLevel::Debug,                                         \
          ("TouchCaret (%p): %s:%d : " message "\n", this, __FUNCTION__,        \
           __LINE__, ##__VA_ARGS__));
 
@@ -74,20 +74,16 @@ TouchCaret::TouchCaret(nsIPresShell* aPr
     mCaretCenterToDownPointOffsetY(0),
     mInAsyncPanZoomGesture(false),
     mVisible(false),
     mIsValidTap(false),
     mActionBarViewID(0)
 {
   MOZ_ASSERT(NS_IsMainThread());
 
-  if (!gTouchCaretLog) {
-    gTouchCaretLog = PR_NewLogModule(kTouchCaretLogModuleName);
-  }
-
   TOUCHCARET_LOG("Constructor, PresShell=%p", aPresShell);
 
   static bool addedTouchCaretPref = false;
   if (!addedTouchCaretPref) {
     Preferences::AddIntVarCache(&sTouchCaretInflateSize,
                                 "touchcaret.inflatesize.threshold");
     Preferences::AddIntVarCache(&sTouchCaretExpirationTime,
                                 "touchcaret.expiration.time");

--- a/layout/base/moz.build
+++ b/layout/base/moz.build
@@ -105,17 +105,16 @@ EXPORTS.mozilla += [
     'GeometryUtils.h',
     'PaintTracker.h',
     'RestyleLogging.h',
 ]
 
 UNIFIED_SOURCES += [
     'AccessibleCaret.cpp',
     'AccessibleCaretEventHub.cpp',
-    'AccessibleCaretLogger.cpp',
     'AccessibleCaretManager.cpp',
     'ActiveLayerTracker.cpp',
     'DisplayItemClip.cpp',
     'DisplayListClipState.cpp',
     'FrameLayerBuilder.cpp',
     'FramePropertyTable.cpp',
     'GeometryUtils.cpp',
     'LayoutLogging.cpp',

--- a/layout/base/nsDocumentViewer.cpp
+++ b/layout/base/nsDocumentViewer.cpp
@@ -131,25 +131,19 @@ using namespace mozilla::dom;
 #define BEFOREUNLOAD_REQUIRES_INTERACTION_PREFNAME "dom.require_user_interaction_for_beforeunload"
 
 //-----------------------------------------------------
 // LOGGING
 #include "LayoutLogging.h"
 #include "mozilla/Logging.h"
 
 #ifdef NS_PRINTING
-static PRLogModuleInfo *
-GetPrintingLog()
-{
-  static PRLogModuleInfo *sLog;
-  if (!sLog)
-    sLog = PR_NewLogModule("printing");
-  return sLog;
-}
-#define PR_PL(_p1)  MOZ_LOG(GetPrintingLog(), mozilla::LogLevel::Debug, _p1);
+static mozilla::LazyLogModule gPrintingLog("printing");
+
+#define PR_PL(_p1)  MOZ_LOG(gPrintingLog, mozilla::LogLevel::Debug, _p1);
 #endif // NS_PRINTING
 
 #define PRT_YESNO(_p) ((_p)?"YES":"NO")
 //-----------------------------------------------------
 
 class nsDocumentViewer;
 class nsPrintEventDispatcher;
 

--- a/layout/base/nsPresShell.cpp
+++ b/layout/base/nsPresShell.cpp
@@ -531,17 +531,17 @@ public:
   }
 
 private:
   nsCOMPtr<nsIDocument> mDocument;
 };
 
 bool PresShell::sDisableNonTestMouseEvents = false;
 
-PRLogModuleInfo* PresShell::gLog;
+mozilla::LazyLogModule PresShell::gLog("PresShell");
 
 #ifdef DEBUG
 static void
 VerifyStyleTree(nsPresContext* aPresContext, nsFrameManager* aFrameManager)
 {
   if (nsFrame::GetVerifyStyleTreeEnable()) {
     nsIFrame* rootFrame = aFrameManager->GetRootFrame();
     aPresContext->RestyleManager()->DebugVerifyStyleTree(rootFrame);
@@ -759,19 +759,17 @@ PresShell::PresShell()
   : mMouseLocation(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE)
 {
 #ifdef MOZ_REFLOW_PERF
   mReflowCountMgr = new ReflowCountMgr();
   mReflowCountMgr->SetPresContext(mPresContext);
   mReflowCountMgr->SetPresShell(this);
 #endif
   mLoadBegin = TimeStamp::Now();
-  if (!gLog) {
-    gLog = PR_NewLogModule("PresShell");
-  }
+
   mSelectionFlags = nsISelectionDisplay::DISPLAY_TEXT | nsISelectionDisplay::DISPLAY_IMAGES;
   mIsThemeSupportDisabled = false;
   mIsActive = true;
   // FIXME/bug 735029: find a better solution to this problem
 #ifdef MOZ_WIDGET_ANDROID
   // The java pan/zoom code uses this to mean approximately "request a
   // reset of pan/zoom state" which doesn't necessarily correspond
   // with the first paint of content.
@@ -2460,17 +2458,17 @@ PresShell::BeginLoad(nsIDocument *aDocum
 {
   mDocumentLoading = true;
 
   gfxTextPerfMetrics *tp = nullptr;
   if (mPresContext) {
     tp = mPresContext->GetTextPerfMetrics();
   }
 
-  bool shouldLog = gLog && MOZ_LOG_TEST(gLog, LogLevel::Debug);
+  bool shouldLog = MOZ_LOG_TEST(gLog, LogLevel::Debug);
   if (shouldLog || tp) {
     mLoadBegin = TimeStamp::Now();
   }
 
   if (shouldLog) {
     nsIURI* uri = mDocument->GetDocumentURI();
     nsAutoCString spec;
     if (uri) {
@@ -2496,17 +2494,17 @@ void
 PresShell::LoadComplete()
 {
   gfxTextPerfMetrics *tp = nullptr;
   if (mPresContext) {
     tp = mPresContext->GetTextPerfMetrics();
   }
 
   // log load
-  bool shouldLog = gLog && MOZ_LOG_TEST(gLog, LogLevel::Debug);
+  bool shouldLog = MOZ_LOG_TEST(gLog, LogLevel::Debug);
   if (shouldLog || tp) {
     TimeDuration loadTime = TimeStamp::Now() - mLoadBegin;
     nsIURI* uri = mDocument->GetDocumentURI();
     nsAutoCString spec;
     if (uri) {
       uri->GetSpec(spec);
     }
     if (shouldLog) {

--- a/layout/base/nsPresShell.h
+++ b/layout/base/nsPresShell.h
@@ -330,17 +330,17 @@ public:
 #ifdef DEBUG
   virtual void ListStyleContexts(nsIFrame *aRootFrame, FILE *out,
                                  int32_t aIndent = 0) override;
 
   virtual void ListStyleSheets(FILE *out, int32_t aIndent = 0) override;
   virtual void VerifyStyleTree() override;
 #endif
 
-  static PRLogModuleInfo* gLog;
+  static mozilla::LazyLogModule gLog;
 
   virtual void DisableNonTestMouseEvents(bool aDisable) override;
 
   virtual void UpdateCanvasBackground() override;
 
   virtual void AddCanvasBackgroundColorItem(nsDisplayListBuilder& aBuilder,
                                             nsDisplayList& aList,
                                             nsIFrame* aFrame,

--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@@ -70,18 +70,18 @@
 #include "ipc/Nuwa.h"
 #endif
 
 using namespace mozilla;
 using namespace mozilla::widget;
 using namespace mozilla::ipc;
 using namespace mozilla::layout;
 
-static PRLogModuleInfo *gLog = nullptr;
-#define LOG(...) MOZ_LOG(gLog, mozilla::LogLevel::Debug, (__VA_ARGS__))
+static mozilla::LazyLogModule sRefreshDriverLog("nsRefreshDriver");
+#define LOG(...) MOZ_LOG(sRefreshDriverLog, mozilla::LogLevel::Debug, (__VA_ARGS__))
 
 #define DEFAULT_THROTTLED_FRAME_RATE 1
 #define DEFAULT_RECOMPUTE_VISIBILITY_INTERVAL_MS 1000
 // after 10 minutes, stop firing off inactive timers
 #define DEFAULT_INACTIVE_TIMER_DISABLE_SECONDS 600
 
 namespace mozilla {
 
@@ -766,19 +766,16 @@ GetFirstFrameDelay(imgIRequest* req)
     return 0;
 
   return static_cast<uint32_t>(delay);
 }
 
 /* static */ void
 nsRefreshDriver::InitializeStatics()
 {
-  if (!gLog) {
-    gLog = PR_NewLogModule("nsRefreshDriver");
-  }
 }
 
 /* static */ void
 nsRefreshDriver::Shutdown()
 {
   // clean up our timers
   delete sRegularRateTimer;
   delete sThrottledRateTimer;

--- a/layout/generic/nsFlexContainerFrame.cpp
+++ b/layout/generic/nsFlexContainerFrame.cpp
@@ -28,24 +28,17 @@ using namespace mozilla::layout;
 
 // Convenience typedefs for helper classes that we forward-declare in .h file
 // (so that nsFlexContainerFrame methods can use them as parameters):
 typedef nsFlexContainerFrame::FlexItem FlexItem;
 typedef nsFlexContainerFrame::FlexLine FlexLine;
 typedef nsFlexContainerFrame::FlexboxAxisTracker FlexboxAxisTracker;
 typedef nsFlexContainerFrame::StrutInfo StrutInfo;
 
-static PRLogModuleInfo*
-GetFlexContainerLog()
-{
-  static PRLogModuleInfo *sLog;
-  if (!sLog)
-    sLog = PR_NewLogModule("nsFlexContainerFrame");
-  return sLog;
-}
+static mozilla::LazyLogModule gFlexContainerLog("nsFlexContainerFrame");
 
 // XXXdholbert Some of this helper-stuff should be separated out into a general
 // "main/cross-axis utils" header, shared by grid & flexbox?
 // (Particularly when grid gets support for align-*/justify-* properties.)
 
 // Helper enums
 // ============
 
@@ -2152,17 +2145,17 @@ FlexLine::FreezeOrRestoreEachFlexibleSiz
       item->ClearViolationFlags();
     }
   }
 }
 
 void
 FlexLine::ResolveFlexibleLengths(nscoord aFlexContainerMainSize)
 {
-  MOZ_LOG(GetFlexContainerLog(), LogLevel::Debug, ("ResolveFlexibleLengths\n"));
+  MOZ_LOG(gFlexContainerLog, LogLevel::Debug, ("ResolveFlexibleLengths\n"));
 
   // Determine whether we're going to be growing or shrinking items.
   const bool isUsingFlexGrow =
     (mTotalOuterHypotheticalMainSize < aFlexContainerMainSize);
 
   // Do an "early freeze" for flex items that obviously can't flex in the
   // direction we've chosen:
   FreezeItemsEarly(isUsingFlexGrow);
@@ -2200,17 +2193,17 @@ FlexLine::ResolveFlexibleLengths(nscoord
     nscoord availableFreeSpace = spaceAvailableForFlexItemsContentBoxes;
     for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
       if (!item->IsFrozen()) {
         item->SetMainSize(item->GetFlexBaseSize());
       }
       availableFreeSpace -= item->GetMainSize();
     }
 
-    MOZ_LOG(GetFlexContainerLog(), LogLevel::Debug,
+    MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
            (" available free space = %d\n", availableFreeSpace));
 
 
     // The sign of our free space should agree with the type of flexing
     // (grow/shrink) that we're doing (except if we've had integer overflow;
     // then, all bets are off). Any disagreement should've made us use the
     // other type of flexing, or should've been resolved in FreezeItemsEarly.
     // XXXdholbert If & when bug 765861 is fixed, we should upgrade this
@@ -2312,17 +2305,17 @@ FlexLine::ResolveFlexibleLengths(nscoord
             availableFreeSpace = std::min(availableFreeSpace,
                                           totalDesiredPortionOfOrigFreeSpace);
           } else {
             availableFreeSpace = std::max(availableFreeSpace,
                                           totalDesiredPortionOfOrigFreeSpace);
           }
         }
 
-        MOZ_LOG(GetFlexContainerLog(), LogLevel::Debug,
+        MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
                (" Distributing available space:"));
         // Since this loop only operates on unfrozen flex items, we can break as
         // soon as we have seen all of them.
         numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
 
         // NOTE: It's important that we traverse our items in *reverse* order
         // here, for correct width distribution according to the items'
         // "ShareOfWeightSoFar" progressively-calculated values.
@@ -2360,27 +2353,27 @@ FlexLine::ResolveFlexibleLengths(nscoord
                 NSToCoordRound(availableFreeSpace /
                                float(numItemsWithLargestWeight));
               numItemsWithLargestWeight--;
             }
 
             availableFreeSpace -= sizeDelta;
 
             item->SetMainSize(item->GetMainSize() + sizeDelta);
-            MOZ_LOG(GetFlexContainerLog(), LogLevel::Debug,
+            MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
                    ("  child %p receives %d, for a total of %d\n",
                     item, sizeDelta, item->GetMainSize()));
           }
         }
       }
     }
 
     // Fix min/max violations:
     nscoord totalViolation = 0; // keeps track of adjustments for min/max
-    MOZ_LOG(GetFlexContainerLog(), LogLevel::Debug,
+    MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
            (" Checking for violations:"));
 
     // Since this loop only operates on unfrozen flex items, we can break as
     // soon as we have seen all of them.
     uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
     for (FlexItem* item = mItems.getFirst();
          numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
       MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
@@ -2399,17 +2392,17 @@ FlexLine::ResolveFlexibleLengths(nscoord
           item->SetHadMaxViolation();
         }
       }
     }
 
     FreezeOrRestoreEachFlexibleSize(totalViolation,
                                     iterationCounter + 1 == mNumItems);
 
-    MOZ_LOG(GetFlexContainerLog(), LogLevel::Debug,
+    MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
            (" Total violation: %d\n", totalViolation));
 
     if (mNumFrozenItems == mNumItems) {
       break;
     }
 
     MOZ_ASSERT(totalViolation != 0,
                "Zero violation should've made us freeze all items & break");
@@ -3606,17 +3599,17 @@ void
 nsFlexContainerFrame::Reflow(nsPresContext*           aPresContext,
                              nsHTMLReflowMetrics&     aDesiredSize,
                              const nsHTMLReflowState& aReflowState,
                              nsReflowStatus&          aStatus)
 {
   MarkInReflow();
   DO_GLOBAL_REFLOW_COUNT("nsFlexContainerFrame");
   DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
-  MOZ_LOG(GetFlexContainerLog(), LogLevel::Debug,
+  MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
          ("Reflow() for nsFlexContainerFrame %p\n", this));
 
   if (IsFrameTreeTooDeep(aReflowState, aDesiredSize, aStatus)) {
     return;
   }
 
   // We (and our children) can only depend on our ancestor's bsize if we have
   // a percent-bsize, or if we're positioned and we have "block-start" and "block-end"

--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -209,49 +209,37 @@ bool nsFrame::GetShowEventTargetFrameBor
 {
   return gShowEventTargetFrameBorder;
 }
 
 /**
  * Note: the log module is created during library initialization which
  * means that you cannot perform logging before then.
  */
-static PRLogModuleInfo* gLogModule;
-
-static PRLogModuleInfo* gStyleVerifyTreeLogModuleInfo;
+mozilla::LazyLogModule nsFrame::sFrameLogModule("frame");
+
+static mozilla::LazyLogModule sStyleVerifyTreeLogModuleInfo("styleverifytree");
 
 static uint32_t gStyleVerifyTreeEnable = 0x55;
 
 bool
 nsFrame::GetVerifyStyleTreeEnable()
 {
   if (gStyleVerifyTreeEnable == 0x55) {
-    if (nullptr == gStyleVerifyTreeLogModuleInfo) {
-      gStyleVerifyTreeLogModuleInfo = PR_NewLogModule("styleverifytree");
-      gStyleVerifyTreeEnable = 0 != gStyleVerifyTreeLogModuleInfo->level;
-    }
+      gStyleVerifyTreeEnable = 0 != (int)((mozilla::LogModule*)sStyleVerifyTreeLogModuleInfo)->Level();
   }
   return gStyleVerifyTreeEnable;
 }
 
 void
 nsFrame::SetVerifyStyleTreeEnable(bool aEnabled)
 {
   gStyleVerifyTreeEnable = aEnabled;
 }
 
-PRLogModuleInfo*
-nsFrame::GetLogModuleInfo()
-{
-  if (nullptr == gLogModule) {
-    gLogModule = PR_NewLogModule("frame");
-  }
-  return gLogModule;
-}
-
 #endif
 
 NS_DECLARE_FRAME_PROPERTY(AbsoluteContainingBlockProperty,
                           DeleteValue<nsAbsoluteContainingBlock>)
 
 bool
 nsIFrame::HasAbsolutelyPositionedChildren() const {
   return IsAbsoluteContainer() && GetAbsoluteContainingBlock()->HasAbsoluteFrames();
@@ -9138,40 +9126,40 @@ GetTagName(nsFrame* aFrame, nsIContent* 
   else {
     PR_snprintf(aResult, aResultSize, "@%p", aFrame);
   }
 }
 
 void
 nsFrame::Trace(const char* aMethod, bool aEnter)
 {
-  if (NS_FRAME_LOG_TEST(GetLogModuleInfo(), NS_FRAME_TRACE_CALLS)) {
+  if (NS_FRAME_LOG_TEST(sFrameLogModule, NS_FRAME_TRACE_CALLS)) {
     char tagbuf[40];
     GetTagName(this, mContent, sizeof(tagbuf), tagbuf);
     PR_LogPrint("%s: %s %s", tagbuf, aEnter ? "enter" : "exit", aMethod);
   }
 }
 
 void
 nsFrame::Trace(const char* aMethod, bool aEnter, nsReflowStatus aStatus)
 {
-  if (NS_FRAME_LOG_TEST(GetLogModuleInfo(), NS_FRAME_TRACE_CALLS)) {
+  if (NS_FRAME_LOG_TEST(sFrameLogModule, NS_FRAME_TRACE_CALLS)) {
     char tagbuf[40];
     GetTagName(this, mContent, sizeof(tagbuf), tagbuf);
     PR_LogPrint("%s: %s %s, status=%scomplete%s",
                 tagbuf, aEnter ? "enter" : "exit", aMethod,
                 NS_FRAME_IS_NOT_COMPLETE(aStatus) ? "not" : "",
                 (NS_FRAME_REFLOW_NEXTINFLOW & aStatus) ? "+reflow" : "");
   }
 }
 
 void
 nsFrame::TraceMsg(const char* aFormatString, ...)
 {
-  if (NS_FRAME_LOG_TEST(GetLogModuleInfo(), NS_FRAME_TRACE_CALLS)) {
+  if (NS_FRAME_LOG_TEST(sFrameLogModule, NS_FRAME_TRACE_CALLS)) {
     // Format arguments into a buffer
     char argbuf[200];
     va_list ap;
     va_start(ap, aFormatString);
     PR_vsnprintf(argbuf, sizeof(argbuf), aFormatString, ap);
     va_end(ap);
 
     char tagbuf[40];

--- a/layout/generic/nsFrame.h
+++ b/layout/generic/nsFrame.h
@@ -25,46 +25,46 @@
  * specific type of logging. Each logging operation has associated
  * inline methods defined below.
  */
 #define NS_FRAME_TRACE_CALLS        0x1
 #define NS_FRAME_TRACE_PUSH_PULL    0x2
 #define NS_FRAME_TRACE_CHILD_REFLOW 0x4
 #define NS_FRAME_TRACE_NEW_FRAMES   0x8
 
-#define NS_FRAME_LOG_TEST(_lm,_bit) (int((_lm)->level) & (_bit))
+#define NS_FRAME_LOG_TEST(_lm,_bit) (int(((mozilla::LogModule*)_lm)->Level()) & (_bit))
 
 #ifdef DEBUG
 #define NS_FRAME_LOG(_bit,_args)                                \
   PR_BEGIN_MACRO                                                \
-    if (NS_FRAME_LOG_TEST(nsFrame::GetLogModuleInfo(),_bit)) {  \
+    if (NS_FRAME_LOG_TEST(nsFrame::sFrameLogModule,_bit)) {  \
       PR_LogPrint _args;                                        \
     }                                                           \
   PR_END_MACRO
 #else
 #define NS_FRAME_LOG(_bit,_args)
 #endif
 
 // XXX Need to rework this so that logging is free when it's off
 #ifdef DEBUG
 #define NS_FRAME_TRACE_IN(_method) Trace(_method, true)
 
 #define NS_FRAME_TRACE_OUT(_method) Trace(_method, false)
 
 // XXX remove me
 #define NS_FRAME_TRACE_MSG(_bit,_args)                          \
   PR_BEGIN_MACRO                                                \
-    if (NS_FRAME_LOG_TEST(nsFrame::GetLogModuleInfo(),_bit)) {  \
+    if (NS_FRAME_LOG_TEST(nsFrame::sFrameLogModule,_bit)) {  \
       TraceMsg _args;                                           \
     }                                                           \
   PR_END_MACRO
 
 #define NS_FRAME_TRACE(_bit,_args)                              \
   PR_BEGIN_MACRO                                                \
-    if (NS_FRAME_LOG_TEST(nsFrame::GetLogModuleInfo(),_bit)) {  \
+    if (NS_FRAME_LOG_TEST(nsFrame::sFrameLogModule,_bit)) {  \
       TraceMsg _args;                                           \
     }                                                           \
   PR_END_MACRO
 
 #define NS_FRAME_TRACE_REFLOW_IN(_method) Trace(_method, true)
 
 #define NS_FRAME_TRACE_REFLOW_OUT(_method, _status) \
   Trace(_method, false, _status)
@@ -718,24 +718,17 @@ public:
    */
   static bool GetVerifyStyleTreeEnable();
 
   /**
    * Set the verify-style-tree enable flag.
    */
   static void SetVerifyStyleTreeEnable(bool aEnabled);
 
-  /**
-   * The frame class and related classes share an nspr log module
-   * for logging frame activity.
-   *
-   * Note: the log module is created during library initialization which
-   * means that you cannot perform logging before then.
-   */
-  static PRLogModuleInfo* GetLogModuleInfo();
+  static mozilla::LazyLogModule sFrameLogModule;
 
   // Show frame borders when rendering
   static void ShowFrameBorders(bool aEnable);
   static bool GetShowFrameBorders();
 
   // Show frame border of event target
   static void ShowEventTargetFrameBorder(bool aEnable);
   static bool GetShowEventTargetFrameBorder();

--- a/layout/generic/nsPageFrame.cpp
+++ b/layout/generic/nsPageFrame.cpp
@@ -17,18 +17,18 @@
 #include "nsDisplayList.h"
 #include "nsLayoutUtils.h" // for function BinarySearchForPosition
 #include "nsSimplePageSequenceFrame.h" // for nsSharedPageData
 #include "nsTextFormatter.h" // for page number localization formatting
 #include "nsBidiUtils.h"
 #include "nsIPrintSettings.h"
 
 #include "mozilla/Logging.h"
-extern PRLogModuleInfo *GetLayoutPrintingLog();
-#define PR_PL(_p1)  MOZ_LOG(GetLayoutPrintingLog(), mozilla::LogLevel::Debug, _p1)
+extern mozilla::LazyLogModule gLayoutPrintingLog;
+#define PR_PL(_p1)  MOZ_LOG(gLayoutPrintingLog, mozilla::LogLevel::Debug, _p1)
 
 using namespace mozilla;
 using namespace mozilla::gfx;
 
 nsPageFrame*
 NS_NewPageFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
   return new (aPresShell) nsPageFrame(aContext);

--- a/layout/generic/nsPluginFrame.cpp
+++ b/layout/generic/nsPluginFrame.cpp
@@ -89,24 +89,17 @@ using mozilla::DefaultXDisplay;
 #endif
 
 #include "mozilla/dom/TabChild.h"
 
 #ifdef CreateEvent // Thank you MS.
 #undef CreateEvent
 #endif
 
-static PRLogModuleInfo *
-GetObjectFrameLog()
-{
-  static PRLogModuleInfo *sLog;
-  if (!sLog)
-    sLog = PR_NewLogModule("nsPluginFrame");
-  return sLog;
-}
+static mozilla::LazyLogModule sPluginFrameLog("nsPluginFrame");
 
 using namespace mozilla;
 using namespace mozilla::gfx;
 using namespace mozilla::layers;
 
 class PluginBackgroundSink : public ReadbackSink {
 public:
   PluginBackgroundSink(nsPluginFrame* aFrame, uint64_t aStartSequenceNumber)
@@ -155,23 +148,23 @@ protected:
 };
 
 nsPluginFrame::nsPluginFrame(nsStyleContext* aContext)
   : nsPluginFrameSuper(aContext)
   , mInstanceOwner(nullptr)
   , mReflowCallbackPosted(false)
   , mIsHiddenDueToScroll(false)
 {
-  MOZ_LOG(GetObjectFrameLog(), LogLevel::Debug,
+  MOZ_LOG(sPluginFrameLog, LogLevel::Debug,
          ("Created new nsPluginFrame %p\n", this));
 }
 
 nsPluginFrame::~nsPluginFrame()
 {
-  MOZ_LOG(GetObjectFrameLog(), LogLevel::Debug,
+  MOZ_LOG(sPluginFrameLog, LogLevel::Debug,
          ("nsPluginFrame %p deleted\n", this));
 }
 
 NS_QUERYFRAME_HEAD(nsPluginFrame)
   NS_QUERYFRAME_ENTRY(nsPluginFrame)
   NS_QUERYFRAME_ENTRY(nsIObjectFrame)
 NS_QUERYFRAME_TAIL_INHERITING(nsPluginFrameSuper)
 
@@ -191,17 +184,17 @@ NS_IMETHODIMP nsPluginFrame::GetPluginPo
 #endif
 #endif
 
 void
 nsPluginFrame::Init(nsIContent*       aContent,
                     nsContainerFrame* aParent,
                     nsIFrame*         aPrevInFlow)
 {
-  MOZ_LOG(GetObjectFrameLog(), LogLevel::Debug,
+  MOZ_LOG(sPluginFrameLog, LogLevel::Debug,
          ("Initializing nsPluginFrame %p for content %p\n", this, aContent));
 
   nsPluginFrameSuper::Init(aContent, aParent, aPrevInFlow);
 }
 
 void
 nsPluginFrame::DestroyFrom(nsIFrame* aDestructRoot)
 {

--- a/layout/generic/nsSimplePageSequenceFrame.cpp
+++ b/layout/generic/nsSimplePageSequenceFrame.cpp
@@ -37,25 +37,19 @@
 using namespace mozilla;
 using namespace mozilla::dom;
 
 static const char sPrintOptionsContractID[] = "@mozilla.org/gfx/printsettings-service;1";
 
 //
 
 #include "mozilla/Logging.h"
-PRLogModuleInfo *
-GetLayoutPrintingLog()
-{
-  static PRLogModuleInfo *sLog;
-  if (!sLog)
-    sLog = PR_NewLogModule("printing-layout");
-  return sLog;
-}
-#define PR_PL(_p1)  MOZ_LOG(GetLayoutPrintingLog(), mozilla::LogLevel::Debug, _p1)
+mozilla::LazyLogModule gLayoutPrintingLog("printing-layout");
+
+#define PR_PL(_p1)  MOZ_LOG(gLayoutPrintingLog, mozilla::LogLevel::Debug, _p1)
 
 nsSimplePageSequenceFrame*
 NS_NewSimplePageSequenceFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
   return new (aPresShell) nsSimplePageSequenceFrame(aContext);
 }
 
 NS_IMPL_FRAMEARENA_HELPERS(nsSimplePageSequenceFrame)

--- a/layout/printing/nsPrintData.cpp
+++ b/layout/printing/nsPrintData.cpp
@@ -12,25 +12,19 @@
 #include "nsIWebProgressListener.h"
 #include "mozilla/Services.h"
 
 //-----------------------------------------------------
 // PR LOGGING
 #include "mozilla/Logging.h"
 
 #define DUMP_LAYOUT_LEVEL 9 // this turns on the dumping of each doucment's layout info
-static PRLogModuleInfo *
-GetPrintingLog()
-{
-  static PRLogModuleInfo *sLog;
-  if (!sLog)
-    sLog = PR_NewLogModule("printing");
-  return sLog;
-}
-#define PR_PL(_p1)  MOZ_LOG(GetPrintingLog(), mozilla::LogLevel::Debug, _p1);
+static mozilla::LazyLogModule gPrintingLog("printing");
+
+#define PR_PL(_p1)  MOZ_LOG(gPrintingLog, mozilla::LogLevel::Debug, _p1);
 
 //---------------------------------------------------
 //-- nsPrintData Class Impl
 //---------------------------------------------------
 nsPrintData::nsPrintData(ePrintDataType aType) :
   mType(aType), mDebugFilePtr(nullptr), mPrintObject(nullptr), mSelectedPO(nullptr),
   mPrintDocList(0), mIsIFrameSelected(false),
   mIsParentAFrameSet(false), mOnStartSent(false),

--- a/layout/printing/nsPrintEngine.cpp
+++ b/layout/printing/nsPrintEngine.cpp
@@ -135,25 +135,19 @@ using namespace mozilla::dom;
 // PR_LOGGING is force to always be on (even in release builds)
 // but we only want some of it on,
 //#define EXTENDED_DEBUG_PRINTING 
 #endif
 
 #define DUMP_LAYOUT_LEVEL 9 // this turns on the dumping of each doucment's layout info
 
 #ifndef PR_PL
-static PRLogModuleInfo *
-GetPrintingLog()
-{
-  static PRLogModuleInfo *sLog;
-  if (!sLog)
-    sLog = PR_NewLogModule("printing");
-  return sLog;
-}
-#define PR_PL(_p1)  MOZ_LOG(GetPrintingLog(), mozilla::LogLevel::Debug, _p1);
+static mozilla::LazyLogModule gPrintingLog("printing")
+
+#define PR_PL(_p1)  MOZ_LOG(gPrintingLog, mozilla::LogLevel::Debug, _p1);
 #endif
 
 #ifdef EXTENDED_DEBUG_PRINTING
 static uint32_t gDumpFileNameCnt   = 0;
 static uint32_t gDumpLOFileNameCnt = 0;
 #endif
 
 #define PRT_YESNO(_p) ((_p)?"YES":"NO")
@@ -1639,17 +1633,17 @@ nsPrintEngine::SetupToPrintContent()
     }
 
     if (mPrt->mShrinkRatio < 0.998f) {
       rv = ReconstructAndReflow(true);
       didReconstruction = true;
       NS_ENSURE_SUCCESS(rv, rv);
     }
 
-    if (MOZ_LOG_TEST(GetPrintingLog(), LogLevel::Debug)) {
+    if (MOZ_LOG_TEST(gPrintingLog, LogLevel::Debug)) {
       float calcRatio = 0.0f;
       if (mPrt->mPrintDocList.Length() > 1 && mPrt->mPrintObject->mFrameType == eFrameSet) {
         nsPrintObject* smallestPO = FindSmallestSTF();
         NS_ASSERTION(smallestPO, "There must always be an XMost PO!");
         if (smallestPO) {
           // Calc the shrinkage based on the entire content area
           calcRatio = smallestPO->mShrinkRatio;
         }

--- a/layout/style/Loader.cpp
+++ b/layout/style/Loader.cpp
@@ -261,43 +261,28 @@ public:
   nsresult                              mStatus;
 
 private:
   void FireLoadEvent(nsIThreadInternal* aThread);
 };
 
 #include "mozilla/Logging.h"
 
-static PRLogModuleInfo *
-GetLoaderLog()
-{
-  static PRLogModuleInfo *sLog;
-  if (!sLog)
-    sLog = PR_NewLogModule("nsCSSLoader");
-  return sLog;
-}
+static mozilla::LazyLogModule sCssLoaderLog("nsCSSLoader");
+
+static mozilla::LazyLogModule gSriPRLog("SRI");
 
-static PRLogModuleInfo*
-GetSriLog()
-{
-  static PRLogModuleInfo *gSriPRLog;
-  if (!gSriPRLog) {
-    gSriPRLog = PR_NewLogModule("SRI");
-  }
-  return gSriPRLog;
-}
-
-#define LOG_ERROR(args) MOZ_LOG(GetLoaderLog(), mozilla::LogLevel::Error, args)
-#define LOG_WARN(args) MOZ_LOG(GetLoaderLog(), mozilla::LogLevel::Warning, args)
-#define LOG_DEBUG(args) MOZ_LOG(GetLoaderLog(), mozilla::LogLevel::Debug, args)
+#define LOG_ERROR(args) MOZ_LOG(sCssLoaderLog, mozilla::LogLevel::Error, args)
+#define LOG_WARN(args) MOZ_LOG(sCssLoaderLog, mozilla::LogLevel::Warning, args)
+#define LOG_DEBUG(args) MOZ_LOG(sCssLoaderLog, mozilla::LogLevel::Debug, args)
 #define LOG(args) LOG_DEBUG(args)
 
-#define LOG_ERROR_ENABLED() MOZ_LOG_TEST(GetLoaderLog(), mozilla::LogLevel::Error)
-#define LOG_WARN_ENABLED() MOZ_LOG_TEST(GetLoaderLog(), mozilla::LogLevel::Warning)
-#define LOG_DEBUG_ENABLED() MOZ_LOG_TEST(GetLoaderLog(), mozilla::LogLevel::Debug)
+#define LOG_ERROR_ENABLED() MOZ_LOG_TEST(sCssLoaderLog, mozilla::LogLevel::Error)
+#define LOG_WARN_ENABLED() MOZ_LOG_TEST(sCssLoaderLog, mozilla::LogLevel::Warning)
+#define LOG_DEBUG_ENABLED() MOZ_LOG_TEST(sCssLoaderLog, mozilla::LogLevel::Debug)
 #define LOG_ENABLED() LOG_DEBUG_ENABLED()
 
 #define LOG_URI(format, uri)                        \
   PR_BEGIN_MACRO                                    \
     NS_ASSERTION(uri, "Logging null uri");          \
     if (LOG_ENABLED()) {                            \
       nsAutoCString _logURISpec;                    \
       uri->GetSpec(_logURISpec);                    \
@@ -977,17 +962,17 @@ SheetLoadData::OnStreamComplete(nsIUnich
   }
 
   SRIMetadata sriMetadata = mSheet->GetIntegrity();
   if (!sriMetadata.IsEmpty() &&
       NS_FAILED(SRICheck::VerifyIntegrity(sriMetadata, aLoader,
                                           mSheet->GetCORSMode(), aBuffer,
                                           mLoader->mDocument))) {
     LOG(("  Load was blocked by SRI"));
-    MOZ_LOG(GetSriLog(), mozilla::LogLevel::Debug,
+    MOZ_LOG(gSriPRLog, mozilla::LogLevel::Debug,
             ("css::Loader::OnStreamComplete, bad metadata"));
     mLoader->SheetComplete(this, NS_ERROR_SRI_CORRUPT);
     return NS_OK;
   }
 
   // Enough to set the URIs on mSheet, since any sibling datas we have share
   // the same mInner as mSheet and will thus get the same URI.
   mSheet->SetURIs(channelURI, originalURI, channelURI);
@@ -1266,17 +1251,17 @@ Loader::CreateSheet(nsIURI* aURI,
     } else {
       baseURI = aURI;
       sheetURI = aURI;
       originalURI = aURI;
     }
 
     SRIMetadata sriMetadata;
     if (!aIntegrity.IsEmpty()) {
-      MOZ_LOG(GetSriLog(), mozilla::LogLevel::Debug,
+      MOZ_LOG(gSriPRLog, mozilla::LogLevel::Debug,
               ("css::Loader::CreateSheet, integrity=%s",
                NS_ConvertUTF16toUTF8(aIntegrity).get()));
       SRICheck::IntegrityMetadata(aIntegrity, mDocument, &sriMetadata);
     }
 
     RefPtr<CSSStyleSheet> sheet = new CSSStyleSheet(aCORSMode,
                                                       aReferrerPolicy,
                                                       sriMetadata);