Bug 726580, Stop shadowing PlanarYCbCr::mOffscreenFormat, r=bas

gfx/layers/basic/BasicImages.cpp

@@ -62,8 +62,9 @@ public:
   BasicPlanarYCbCrImage(const gfxIntSize& aScaleHint, gfxImageFormat aOffscreenFormat, BufferRecycleBin *aRecycleBin)
     : PlanarYCbCrImage(aRecycleBin)
     , mScaleHint(aScaleHint)
-    , mOffscreenFormat(aOffscreenFormat)
-  {}
+  {
+    SetOffscreenFormat(aOffscreenFormat);
+  }
 
   ~BasicPlanarYCbCrImage()
   {
@@ -79,7 +80,6 @@ public:
 
 private:
   gfxIntSize mScaleHint;
-  gfxImageFormat mOffscreenFormat;
   int mStride;
   nsAutoArrayPtr<PRUint8> mDecodedBuffer;
 };