Bug 874721; Re-fix WebGL. r=mattwoodrow

gfx/thebes/gfxCachedTempSurface.cpp

@@ -73,11 +73,9 @@ gfxCachedTempSurface::Get(gfxASurface::gfxContentType aContentType,
   if (mSurface) {
     /* Verify the current buffer is valid for this purpose */
     if (mSize.width < aRect.width || mSize.height < aRect.height
-        || mSurface->GetContentType() != aContentType) {
+        || mSurface->GetContentType() != aContentType
+        || mType != aSimilarTo->GetType()) {
       mSurface = nullptr;
-    } else {
-      NS_ASSERTION(mType == aSimilarTo->GetType(),
-                   "Unexpected surface type change");
     }
   }
 
@@ -89,9 +87,7 @@ gfxCachedTempSurface::Get(gfxASurface::gfxContentType aContentType,
       return nullptr;
 
     cleared = true;
-#ifdef DEBUG
     mType = aSimilarTo->GetType();
-#endif
   }
   mSurface->SetDeviceOffset(-aRect.TopLeft());
 

gfx/thebes/gfxCachedTempSurface.h

@@ -33,10 +33,9 @@ public:
    * When |aContentType| differs in different invocations this is handled
    * appropriately, creating a new surface if necessary.
    * 
-   * |aSimilarTo| should be of the same gfxSurfaceType in each invocation.
    * Because the cached surface may have been created during a previous
    * invocation, this will not be efficient if the new |aSimilarTo| has a
-   * different format.
+   * different format, size, or gfxSurfaceType.
    */
   already_AddRefed<gfxContext> Get(gfxASurface::gfxContentType aContentType,
                                    const gfxRect& aRect,
@@ -52,9 +51,7 @@ private:
   nsRefPtr<gfxASurface> mSurface;
   gfxIntSize mSize;
   nsExpirationState mExpirationState;
-#ifdef DEBUG
   gfxASurface::gfxSurfaceType mType;
-#endif 
 };
 
 #endif /* GFX_CACHED_TEMP_SURFACE_H */