--- a/gfx/layers/ThebesLayerBuffer.h
+++ b/gfx/layers/ThebesLayerBuffer.h
@@ -57,26 +57,30 @@ public:
 
   RotatedBuffer(gfxASurface* aBuffer, gfxASurface* aBufferOnWhite,
                 const nsIntRect& aBufferRect,
                 const nsIntPoint& aBufferRotation)
     : mBuffer(aBuffer)
     , mBufferOnWhite(aBufferOnWhite)
     , mBufferRect(aBufferRect)
     , mBufferRotation(aBufferRotation)
+    , mDidSelfCopy(false)
   { }
   RotatedBuffer(gfx::DrawTarget* aDTBuffer, gfx::DrawTarget* aDTBufferOnWhite,
                 const nsIntRect& aBufferRect,
                 const nsIntPoint& aBufferRotation)
     : mDTBuffer(aDTBuffer)
     , mDTBufferOnWhite(aDTBufferOnWhite)
     , mBufferRect(aBufferRect)
     , mBufferRotation(aBufferRotation)
+    , mDidSelfCopy(false)
   { }
-  RotatedBuffer() { }
+  RotatedBuffer()
+    : mDidSelfCopy(false)
+  { }
 
   /*
    * Which buffer should be drawn to/read from.
    */
   enum ContextSource {
     BUFFER_BLACK, // The normal buffer, or buffer with black background when using component alpha.
     BUFFER_WHITE, // The buffer with white background, only valid with component alpha.
     BUFFER_BOTH // The combined black/white buffers, only valid for writing operations, not reading.