--- a/gfx/ipc/GraphicsMessages.ipdlh
+++ b/gfx/ipc/GraphicsMessages.ipdlh
@@ -7,17 +7,17 @@
 
 using struct DxgiAdapterDesc from "mozilla/D3DMessageUtils.h";
 
 namespace mozilla {
 namespace gfx {
 
 struct DeviceInitData
 {
-  bool useAcceleration;
+  bool useHwCompositing;
 
   // Windows only.
   bool useD3D11;
   bool useD3D11WARP;
   bool useD3D11ImageBridge;
   bool d3d11TextureSharingWorks;
   bool useD2D1;
   DxgiAdapterDesc adapter;

--- a/gfx/thebes/gfxPlatform.cpp
+++ b/gfx/thebes/gfxPlatform.cpp
@@ -165,16 +165,20 @@ static qcms_profile *gCMSsRGBProfile = n
 
 static qcms_transform *gCMSRGBTransform = nullptr;
 static qcms_transform *gCMSInverseRGBTransform = nullptr;
 static qcms_transform *gCMSRGBATransform = nullptr;
 
 static bool gCMSInitialized = false;
 static eCMSMode gCMSMode = eCMSMode_Off;
 
+// Device init data should only be used on child processes, so we protect it
+// behind a getter here.
+static DeviceInitData sDeviceInitDataDoNotUseDirectly;
+
 static void ShutdownCMS();
 
 #include "mozilla/gfx/2D.h"
 #include "mozilla/gfx/SourceSurfaceCairo.h"
 using namespace mozilla::gfx;
 
 /* Class to listen for pref changes so that chrome code can dynamically
    force sRGB as an output profile. See Bug #452125. */
@@ -2231,16 +2235,23 @@ gfxPlatform::GetScaledFontForFontWithCai
         nativeFont.mType = NativeFontType::CAIRO_FONT_FACE;
         nativeFont.mFont = aFont->GetCairoScaledFont();
         return Factory::CreateScaledFontForNativeFont(nativeFont, aFont->GetAdjustedSize());
     }
 
     return nullptr;
 }
 
+/* static */ DeviceInitData&
+gfxPlatform::GetParentDevicePrefs()
+{
+  MOZ_ASSERT(XRE_IsContentProcess());
+  return sDeviceInitDataDoNotUseDirectly;
+}
+
 /* static */ bool
 gfxPlatform::UsesOffMainThreadCompositing()
 {
   static bool firstTime = true;
   static bool result = false;
 
   if (firstTime) {
     MOZ_ASSERT(sLayersAccelerationPrefsInitialized);
@@ -2437,31 +2448,31 @@ gfxPlatform::NotifyCompositorCreated(Lay
     }
   }));
 }
 
 void
 gfxPlatform::GetDeviceInitData(mozilla::gfx::DeviceInitData* aOut)
 {
   MOZ_ASSERT(XRE_IsParentProcess());
-  aOut->useAcceleration() = gfxConfig::IsEnabled(Feature::HW_COMPOSITING);
+  aOut->useHwCompositing() = gfxConfig::IsEnabled(Feature::HW_COMPOSITING);
 }
 
 void
 gfxPlatform::UpdateDeviceInitData()
 {
   if (XRE_IsParentProcess()) {
     // The parent process figures out device initialization on its own.
     return;
   }
 
   mozilla::gfx::DeviceInitData data;
   mozilla::dom::ContentChild::GetSingleton()->SendGetGraphicsDeviceInitData(&data);
 
-  SetDeviceInitData(data);
+  sDeviceInitDataDoNotUseDirectly = data;
 }
 
 bool
 gfxPlatform::SupportsApzDragInput() const
 {
   return gfxPrefs::APZDragEnabled();
 }
 

--- a/gfx/thebes/gfxPlatform.h
+++ b/gfx/thebes/gfxPlatform.h
@@ -689,22 +689,16 @@ protected:
     void UpdateDeviceInitData();
 
     /**
      * Increase the global device counter after a device has been removed/reset.
      */
     void BumpDeviceCounter();
 
     /**
-     * Called when new device preferences are available.
-     */
-    virtual void SetDeviceInitData(mozilla::gfx::DeviceInitData& aData)
-    {}
-
-    /**
      * returns the first backend named in the pref gfx.canvas.azure.backends
      * which is a component of aBackendBitmask, a bitmask of backend types
      */
     static mozilla::gfx::BackendType GetCanvasBackendPref(uint32_t aBackendBitmask);
 
     /**
      * returns the first backend named in the pref gfx.content.azure.backend
      * which is a component of aBackendBitmask, a bitmask of backend types
@@ -722,16 +716,18 @@ protected:
     /**
      * Decode the backend enumberation from a string.
      */
     static mozilla::gfx::BackendType BackendTypeForName(const nsCString& aName);
 
     static already_AddRefed<mozilla::gfx::ScaledFont>
       GetScaledFontForFontWithCairoSkia(mozilla::gfx::DrawTarget* aTarget, gfxFont* aFont);
 
+    static mozilla::gfx::DeviceInitData& GetParentDevicePrefs();
+
     int8_t  mAllowDownloadableFonts;
     int8_t  mGraphiteShapingEnabled;
     int8_t  mOpenTypeSVGEnabled;
 
     int8_t  mBidiNumeralOption;
 
     // whether to always search font cmaps globally 
     // when doing system font fallback

--- a/gfx/thebes/gfxWindowsPlatform.cpp
+++ b/gfx/thebes/gfxWindowsPlatform.cpp
@@ -353,26 +353,16 @@ public:
     return MOZ_COLLECT_REPORT("d3d9-shared-texture", KIND_OTHER, UNITS_BYTES,
                               gfxWindowsPlatform::sD3D9SharedTextureUsed,
                               "Memory used for D3D9 shared textures");
   }
 };
 
 NS_IMPL_ISUPPORTS(D3D9SharedTextureReporter, nsIMemoryReporter)
 
-// Device init data should only be used on child processes, so we protect it
-// behind a getter here.
-static DeviceInitData sDeviceInitDataDoNotUseDirectly;
-static inline DeviceInitData&
-GetParentDevicePrefs()
-{
-  MOZ_ASSERT(XRE_IsContentProcess());
-  return sDeviceInitDataDoNotUseDirectly;
-}
-
 gfxWindowsPlatform::gfxWindowsPlatform()
   : mRenderMode(RENDER_GDI)
   , mDeviceLock("gfxWindowsPlatform.mDeviceLock")
   , mIsWARP(false)
   , mHasDeviceReset(false)
   , mHasFakeDeviceReset(false)
   , mCompositorD3D11TextureSharingWorks(false)
   , mAcceleration(FeatureStatus::Unused)
@@ -1922,18 +1912,18 @@ bool DoesD3D11TextureSharingWork(ID3D11D
   return DoesD3D11TextureSharingWorkInternal(device, DXGI_FORMAT_B8G8R8A8_UNORM, D3D11_BIND_RENDER_TARGET | D3D11_BIND_SHADER_RESOURCE);
 }
 
 bool DoesD3D11AlphaTextureSharingWork(ID3D11Device *device)
 {
   return DoesD3D11TextureSharingWorkInternal(device, DXGI_FORMAT_R8_UNORM, D3D11_BIND_SHADER_RESOURCE);
 }
 
-static inline bool
-CanUseWARP()
+bool
+gfxWindowsPlatform::CanUseWARP()
 {
   if (gfxPrefs::LayersD3D11ForceWARP()) {
     return true;
   }
 
   // The child process can only use WARP if the parent process is also using
   // WARP.
   if (XRE_IsContentProcess()) {
@@ -2261,23 +2251,16 @@ gfxWindowsPlatform::AttemptD3D11ImageBri
 
   if (XRE_IsContentProcess()) {
     ContentAdapterIsParentAdapter(mD3D11ImageBridgeDevice);
   }
   return FeatureStatus::Available;
 }
 
 void
-gfxWindowsPlatform::SetDeviceInitData(mozilla::gfx::DeviceInitData& aData)
-{
-  MOZ_ASSERT(XRE_IsContentProcess());
-  sDeviceInitDataDoNotUseDirectly = aData;
-}
-
-void
 gfxWindowsPlatform::InitializeDevices()
 {
   // If acceleration is disabled, we refuse to initialize anything.
   mAcceleration = CheckAccelerationSupport();
   if (IsFeatureStatusFailure(mAcceleration)) {
     return;
   }
 
@@ -2320,17 +2303,17 @@ gfxWindowsPlatform::InitializeDevices()
 FeatureStatus
 gfxWindowsPlatform::CheckAccelerationSupport()
 {
   // Don't retry acceleration if it failed earlier.
   if (IsFeatureStatusFailure(mAcceleration)) {
     return mAcceleration;
   }
   if (XRE_IsContentProcess()) {
-    return GetParentDevicePrefs().useAcceleration()
+    return GetParentDevicePrefs().useHwCompositing()
            ? FeatureStatus::Available
            : FeatureStatus::Blocked;
   }
   return gfxConfig::GetValue(Feature::HW_COMPOSITING);
 }
 
 bool
 gfxWindowsPlatform::CanUseD3D11ImageBridge()

--- a/gfx/thebes/gfxWindowsPlatform.h
+++ b/gfx/thebes/gfxWindowsPlatform.h
@@ -265,17 +265,16 @@ public:
     bool SupportsPluginDirectDXGIDrawing();
 
 protected:
     bool AccelerateLayersByDefault() override {
       return true;
     }
     void GetAcceleratedCompositorBackends(nsTArray<mozilla::layers::LayersBackend>& aBackends) override;
     virtual void GetPlatformCMSOutputProfile(void* &mem, size_t &size) override;
-    void SetDeviceInitData(mozilla::gfx::DeviceInitData& aData) override;
 
 protected:
     RenderMode mRenderMode;
 
     int8_t mUseClearTypeForDownloadableFonts;
     int8_t mUseClearTypeAlways;
 
 private:
@@ -308,16 +307,17 @@ private:
     bool AttemptD3D11ImageBridgeDeviceCreationHelper(
         IDXGIAdapter1* aAdapter, HRESULT& aResOut);
     mozilla::gfx::FeatureStatus AttemptD3D11ImageBridgeDeviceCreation();
 
     mozilla::gfx::FeatureStatus AttemptD3D11ContentDeviceCreation();
     bool AttemptD3D11ContentDeviceCreationHelper(
         IDXGIAdapter1* aAdapter, HRESULT& aResOut);
 
+    bool CanUseWARP();
     bool CanUseD3D11ImageBridge();
     bool ContentAdapterIsParentAdapter(ID3D11Device* device);
 
     void DisableD3D11AfterCrash();
     void ResetD3D11Devices();
 
     IDXGIAdapter1 *GetDXGIAdapter();
     bool IsDeviceReset(HRESULT hr, DeviceResetReason* aReason);