import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1250873 - Rename HasInternalBuffer into HasIntermediateBuffer in layers. r=sotaro (578235105f)
- Bug 1256045 - Add a null-check in BufferTextureHost::EnsureWrappingTextureSource. r=jnicol (943c73559d)
- Bug 1251726 - Check if Compositor is set r=nical (550d5b0164)
- Bug 1251427 - Require a full update when a TextureHost switches from a TextureSource to another. r=sotaro (bc59ac4cd7)
- Bug 1256693 - ISurfaceAllocator cleanup. r=sotaro (098e824d4d)
- Bug 1257939 - initialize BGRX alpha channel to opaque when clearing and ignore uninitialized alpha in texture clients. r=mchang (73d778496f)
- more of reapply Bug 1200595 - Consolidate the TextureClient's destruction logic (74517415ed)
- Bug 1256693 - Refer to ClientIPCAllocator instead of ISurfaceAllocator where it makes sense. r=sotaro (e81f2dd923)
- Bug 1236112 - Block on d3d9 video frames to complete before returning them from the decoder. r=cpearce (25114bb3c4)
- Bug 1196409 - Disable D3D11-DXVA for resolutions not supported in hardware. r=jya (3007b1ebff)
- Bug 1196411 - Disable DXVA on 60fps 1080p videos for AMD cards that can't decode quick enough. r=jya (9f8f67e12b)
- Bug 1200775 - Check intel specific h264 decoder when checking for DXVA support. r=cpearce (e7bcbb10be)
- Bug 1257013 - Part 1: Use readback to synchronize d3d9 video. r=cpearce,Bas (d247a9bed6)
- Bug 1257013 - Part 2: Use readback to synchronize d3d11 video. r=cpearce,Bas (43883c1607)
- missing bit of Bug 1206568: P2 (58de11b22f)
- Bug 1239093 - Add pref to allow overriding of hardcoded DXVA blacklist. r=jrmuizel (dfd5e57c2f)
- Bug 1217185: To allow for sandboxing, use null HWNDs when creating the D3D device for video decoding. r=mattwoodrow (0c96e66a47)
- Bug 1200775 - Followup to fix typo and indent issues (b1d1c76788)
- bits of  Bug 1207245 - part 3 (52a1939b74)
- Bug 1224199 - Don't make the TextureClient wait for compositor recycle if the GLContext is shutting down - r=nical (9a0081f217)
- more of Bug 1200595 (047201fd60)
- Bug 1253094, part 2 - Stop using DebugOnly for class/struct members in gfx/. r=Bas (bab6569366)

dom/media/MediaDecoderStateMachine.cpp

@@ -48,6 +48,7 @@
 #include "TimeUnits.h"
 #include "VideoSegment.h"
 #include "VideoUtils.h"
+#include "gfxPrefs.h"
 
 namespace mozilla {
 
@@ -2442,7 +2443,7 @@ MediaDecoderStateMachine::CheckFrameValidity(VideoData* aData)
   MOZ_ASSERT(OnTaskQueue());
 
   // Update corrupt-frames statistics
-  if (aData->mImage && !aData->mImage->IsValid()) {
+  if (aData->mImage && !aData->mImage->IsValid() && !gfxPrefs::HardwareVideoDecodingForceEnabled()) {
     FrameStatistics& frameStats = *mFrameStats;
     frameStats.NotifyCorruptFrame();
     // If more than 10% of the last 30 frames have been corrupted, then try disabling