Fix gpu memory accounting for auto-resolving MSAA.

src/gpu/gl/GrGLRenderTarget.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrGLRenderTarget_DEFINED
 #define GrGLRenderTarget_DEFINED
@@ skipping 68 matching lines @@
 
     // We track this separately from GrGpuResource because this may be both a texture and a render
     // target, and the texture may be wrapped while the render target is not.
     bool fIsWrapped;
 
     // when we switch to this render target we want to set the viewport to
     // only render to content area (as opposed to the whole allocation) and
     // we want the rendering to be at top left (GL has origin in bottom left)
     GrGLIRect fViewport;
 
-    // onGpuMemorySize() needs to know what how many color values are owned per pixel. However,
-    // abandon and release zero out the IDs and the cache needs to know the size even after those
-    // actions.
-    uint8_t fColorValuesPerPixel;
+    // onGpuMemorySize() needs to know the VRAM footprint of the FBO(s). However, abandon and
+    // release zero out the IDs and the cache needs to know the size even after those actions.
+    size_t fGpuMemorySize;
 
     typedef GrRenderTarget INHERITED;
 };
 
 #endif