Bug 1462355 - Part 9. Lock animated imgFrame objects at creation rather than deferring. r=tnikkel

image/Decoder.cpp

@@ -356,8 +356,6 @@ Decoder::AllocateFrameInternal(const gfx::IntSize& aOutputSize,
 
   if (frameNum == 1) {
     MOZ_ASSERT(aPreviousFrame, "Must provide a previous frame when animated");
-    aPreviousFrame->SetRawAccessOnly();
-
     // If we dispose of the first frame by clearing it, then the first frame's
     // refresh area is all of itself.
     // RESTORE_PREVIOUS is invalid (assumed to be DISPOSE_CLEAR).
@@ -370,8 +368,6 @@ Decoder::AllocateFrameInternal(const gfx::IntSize& aOutputSize,
   }
 
   if (frameNum > 0) {
-    ref->SetRawAccessOnly();
-
     // Some GIFs are huge but only have a small area that they animate. We only
     // need to refresh that small area when frame 0 comes around again.
     mFirstFrameRefreshArea.UnionRect(mFirstFrameRefreshArea, frame->GetRect());

image/imgFrame.cpp

@@ -314,6 +314,13 @@ imgFrame::InitForDecoder(const nsIntSize& aImageSize,
     }
   }
 
+  if (aAnimParams) {
+    // We never want to unlock animated frames because we need the raw frame
+    // buffer for blending with future frames. Adding an extra unmatched lock
+    // here will guarantee that.
+    ++mLockCount;
+  }
+
   return NS_OK;
 }
 
@@ -500,16 +507,6 @@ imgFrame::RawAccessRef(bool aOnlyFinished /*= false*/)
   return RawAccessFrameRef(this, aOnlyFinished);
 }
 
-void
-imgFrame::SetRawAccessOnly()
-{
-  AssertImageDataLocked();
-
-  // Lock our data and throw away the key.
-  LockImageData(false);
-}
-
-
 imgFrame::SurfaceWithFormat
 imgFrame::SurfaceForDrawing(bool               aDoPartialDecode,
                             bool               aDoTile,

image/imgFrame.h

@@ -103,18 +103,6 @@ public:
    */
   RawAccessFrameRef RawAccessRef(bool aOnlyFinished = false);
 
-  /**
-   * Make this imgFrame permanently available for raw access.
-   *
-   * This is irrevocable, and should be avoided whenever possible, since it
-   * prevents this imgFrame from being optimized and makes it impossible for its
-   * volatile buffer to be freed.
-   *
-   * It is an error to call this without already holding a RawAccessFrameRef to
-   * this imgFrame.
-   */
-  void SetRawAccessOnly();
-
   bool Draw(gfxContext* aContext, const ImageRegion& aRegion,
             SamplingFilter aSamplingFilter, uint32_t aImageFlags,
             float aOpacity);