Bug 1240264 - Annotate intentional switch fallthroughs in dom/media/. r=cpearce

dom/media/MediaManager.cpp:1905:7 [-Wimplicit-fallthrough] unannotated fall-through between switch labels
dom/media/webm/WebMBufferedParser.cpp:133:7 [-Wimplicit-fallthrough] unannotated fall-through between switch labels

dom/media/MediaManager.cpp

@@ -1925,8 +1925,7 @@ MediaManager::GetUserMedia(nsPIDOMWindow* aWindow,
           nsPIDOMWindow *outer = aWindow->GetOuterWindow();
           vc.mBrowserWindow.Construct(outer->WindowID());
         }
-        // | Fall through
-        // V
+        MOZ_FALLTHROUGH;
       case dom::MediaSourceEnum::Screen:
       case dom::MediaSourceEnum::Application:
       case dom::MediaSourceEnum::Window:

dom/media/VideoUtils.cpp

@@ -252,7 +252,7 @@ already_AddRefed<SharedThreadPool> GetMediaThreadPool(MediaThreadType aType)
       name = "MediaPDecoder";
       break;
     default:
-      MOZ_ASSERT(false);
+      MOZ_FALLTHROUGH_ASSERT("Unexpected MediaThreadType");
     case MediaThreadType::PLAYBACK:
       name = "MediaPlayback";
       break;

dom/media/webaudio/AudioEventTimeline.h

@@ -569,7 +569,7 @@ public:
                                        aPrevious->mCurve, aPrevious->mCurveLength,
                                        aPrevious->mDuration, aTime);
         case AudioTimelineEvent::SetTarget:
-          MOZ_ASSERT(false, "unreached");
+          MOZ_FALLTHROUGH_ASSERT("AudioTimelineEvent::SetTarget");
         case AudioTimelineEvent::SetValue:
         case AudioTimelineEvent::Cancel:
         case AudioTimelineEvent::Stream:
@@ -617,7 +617,7 @@ public:
                                    aPrevious->mCurve, aPrevious->mCurveLength,
                                    aPrevious->mDuration, aTime);
     case AudioTimelineEvent::SetTarget:
-      MOZ_ASSERT(false, "unreached");
+      MOZ_FALLTHROUGH_ASSERT("AudioTimelineEvent::SetTarget");
     case AudioTimelineEvent::SetValue:
     case AudioTimelineEvent::Cancel:
     case AudioTimelineEvent::Stream:

dom/media/webaudio/MediaBufferDecoder.cpp

@@ -570,7 +570,7 @@ WebAudioDecodeJob::OnFailure(ErrorCode aErrorCode)
   const char* errorMessage;
   switch (aErrorCode) {
   case NoError:
-    MOZ_ASSERT(false, "Who passed NoError to OnFailure?");
+    MOZ_FALLTHROUGH_ASSERT("Who passed NoError to OnFailure?");
     // Fall through to get some sort of a sane error message if this actually
     // happens at runtime.
   case UnknownError:

dom/media/webm/WebMBufferedParser.cpp

@@ -133,7 +133,7 @@ void WebMBufferedParser::Append(const unsigned char* aBuffer, uint32_t aLength,
       case EBML_ID:
         mLastInitStartOffset = mCurrentOffset + (p - aBuffer) -
                             (mElement.mID.mLength + mElement.mSize.mLength);
-        /* FALLTHROUGH */
+        MOZ_FALLTHROUGH;
       default:
         mSkipBytes = mElement.mSize.mValue;
         mState = SKIP_DATA;