--- a/gfx/thebes/gfxPlatform.cpp
+++ b/gfx/thebes/gfxPlatform.cpp
@@ -2241,17 +2241,17 @@ gfxPlatform::OptimalFormatForContent(gfx
  * There are a number of layers acceleration (or layers in general) preferences
  * that should be consistent for the lifetime of the application (bug 840967).
  * As such, we will evaluate them all as soon as one of them is evaluated
  * and remember the values.  Changing these preferences during the run will
  * not have any effect until we restart.
  */
 static bool sLayersSupportsD3D9 = false;
 static bool sLayersSupportsD3D11 = false;
-static bool sANGLESupportsD3D11 = false;
+bool gANGLESupportsD3D11 = false;
 static bool sLayersSupportsHardwareVideoDecoding = false;
 static bool sLayersHardwareVideoDecodingFailed = false;
 static bool sBufferRotationCheckPref = true;
 static bool sPrefBrowserTabsRemoteAutostart = false;
 
 static bool sLayersAccelerationPrefsInitialized = false;
 
 void
@@ -2286,17 +2286,17 @@ InitLayersAccelerationPrefs()
         }
       }
       if (!gfxPrefs::LayersD3D11DisableWARP()) {
         // Always support D3D11 when WARP is allowed.
         sLayersSupportsD3D11 = true;
       }
       if (NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_DIRECT3D_11_ANGLE, &status))) {
         if (status == nsIGfxInfo::FEATURE_STATUS_OK) {
-          sANGLESupportsD3D11 = true;
+          gANGLESupportsD3D11 = true;
         }
       }
     }
 #endif
 
     if (Preferences::GetBool("media.hardware-video-decoding.enabled", false) &&
 #ifdef XP_WIN
         Preferences::GetBool("media.windows-media-foundation.use-dxva", true) &&
@@ -2342,17 +2342,17 @@ gfxPlatform::CanUseHardwareVideoDecoding
   MOZ_ASSERT(sLayersAccelerationPrefsInitialized);
   return sLayersSupportsHardwareVideoDecoding && !sLayersHardwareVideoDecodingFailed;
 }
 
 bool
 gfxPlatform::CanUseDirect3D11ANGLE()
 {
   MOZ_ASSERT(sLayersAccelerationPrefsInitialized);
-  return sANGLESupportsD3D11;
+  return gANGLESupportsD3D11;
 }
 
 
 bool
 gfxPlatform::BufferRotationEnabled()
 {
   MutexAutoLock autoLock(*gGfxPlatformPrefsLock);
 

--- a/gfx/thebes/gfxPlatform.h
+++ b/gfx/thebes/gfxPlatform.h
@@ -126,16 +126,18 @@ enum eGfxLog {
     eGfxLog_cmapdata         = 4,
     // text perf data
     eGfxLog_textperf         = 5
 };
 
 // when searching through pref langs, max number of pref langs
 const uint32_t kMaxLenPrefLangList = 32;
 
+extern bool gANGLESupportsD3D11;
+
 #define UNINITIALIZED_VALUE  (-1)
 
 inline const char*
 GetBackendName(mozilla::gfx::BackendType aBackend)
 {
   switch (aBackend) {
       case mozilla::gfx::BackendType::DIRECT2D:
         return "direct2d";

--- a/gfx/thebes/gfxWindowsPlatform.cpp
+++ b/gfx/thebes/gfxWindowsPlatform.cpp
@@ -1713,22 +1713,24 @@ bool DoesD3D11DeviceWork(ID3D11Device *d
   if (GetModuleHandleW(L"dlumd32.dll") && GetModuleHandleW(L"igd10umd32.dll")) {
     nsString displayLinkModuleVersionString;
     gfxWindowsPlatform::GetDLLVersion(L"dlumd32.dll", displayLinkModuleVersionString);
     uint64_t displayLinkModuleVersion;
     if (!ParseDriverVersion(displayLinkModuleVersionString, &displayLinkModuleVersion)) {
 #if defined(MOZ_CRASHREPORTER)
       CrashReporter::AppendAppNotesToCrashReport(NS_LITERAL_CSTRING("DisplayLink: could not parse version\n"));
 #endif
+      gANGLESupportsD3D11 = false;
       return false;
     }
     if (displayLinkModuleVersion <= V(8,6,1,36484)) {
 #if defined(MOZ_CRASHREPORTER)
       CrashReporter::AppendAppNotesToCrashReport(NS_LITERAL_CSTRING("DisplayLink: too old version\n"));
 #endif
+      gANGLESupportsD3D11 = false;
       return false;
     }
   }
   result = true;
   return true;
 }
 
 // See bug 1083071. On some drivers, Direct3D 11 CreateShaderResourceView fails