Refactor ImageBuffer to make OffscreenCanvas match HTMLCanvasElement

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1482 matching lines @@
   if (isContextLost())
     return false;
 
   bool must_clear_now = ClearIfComposited() != kSkipped;
   if (!marked_canvas_dirty_ && !must_clear_now)
     return false;
 
   canvas()->ClearCopiedImage();
   marked_canvas_dirty_ = false;
 
-  if (!canvas()->Buffer())
+  if (!canvas()->GetOrCreateImageBuffer())
     return false;
 
   ScopedTexture2DRestorer restorer(this);
   ScopedFramebufferRestorer fbo_restorer(this);
 
   GetDrawingBuffer()->ResolveAndBindForReadAndDraw();
-  if (!canvas()->Buffer()->CopyRenderingResultsFromDrawingBuffer(
-          GetDrawingBuffer(), source_buffer)) {
+  if (!canvas()
+           ->GetOrCreateImageBuffer()
+           ->CopyRenderingResultsFromDrawingBuffer(GetDrawingBuffer(),
+                                                   source_buffer)) {
     // Currently, copyRenderingResultsFromDrawingBuffer is expected to always
     // succeed because cases where canvas()-buffer() is not accelerated are
     // handle before reaching this point.  If that assumption ever stops holding
     // true, we may need to implement a fallback right here.
     NOTREACHED();
     return false;
   }
 
   return true;
 }
@@ skipping 3436 matching lines @@
 
 void WebGLRenderingContextBase::TexImageCanvasByGPU(
     TexImageFunctionID function_id,
     HTMLCanvasElement* canvas,
     GLenum target,
     GLuint target_texture,
     GLint xoffset,
     GLint yoffset,
     const IntRect& source_sub_rectangle) {
   if (!canvas->Is3d()) {
-    ImageBuffer* buffer = canvas->Buffer();
+    ImageBuffer* buffer = canvas->GetOrCreateImageBuffer();
     if (buffer &&
         !buffer->CopyToPlatformTexture(
             FunctionIDToSnapshotReason(function_id), ContextGL(), target,
             target_texture, unpack_premultiply_alpha_, unpack_flip_y_,
             IntPoint(xoffset, yoffset), source_sub_rectangle)) {
       NOTREACHED();
     }
   } else {
     WebGLRenderingContextBase* gl =
         ToWebGLRenderingContextBase(canvas->RenderingContext());
@@ skipping 2845 matching lines @@
 void WebGLRenderingContextBase::getHTMLOrOffscreenCanvas(
     HTMLCanvasElementOrOffscreenCanvas& result) const {
   if (canvas()) {
     result.setHTMLCanvasElement(static_cast<HTMLCanvasElement*>(host()));
   } else {
     result.setOffscreenCanvas(static_cast<OffscreenCanvas*>(host()));
   }
 }
 
 }  // namespace blink