Make command buffer free transfer buffer when switching tabs

content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if defined(ENABLE_GPU)
 
 #include "content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h"
 
 #include "third_party/khronos/GLES2/gl2.h"
 #ifndef GL_GLEXT_PROTOTYPES
@@ skipping 413 matching lines @@
       target, level, xoffset, yoffset, width, height, format, type, access);
 }
 
 void WebGraphicsContext3DCommandBufferImpl::unmapTexSubImage2DCHROMIUM(
     const void* mem) {
   gl_->UnmapTexSubImage2DCHROMIUM(mem);
 }
 
 void WebGraphicsContext3DCommandBufferImpl::setVisibilityCHROMIUM(
     bool visible) {
-  if (!visible)
-    gl_->FreeUnusedSharedMemory();
   gl_->Flush();
   context_->SetSurfaceVisible(visible);
+  if (!visible)
+    gl_->FreeEverything();
 }
 
 void WebGraphicsContext3DCommandBufferImpl::copyTextureToParentTextureCHROMIUM(
     WebGLId texture, WebGLId parentTexture) {
   NOTIMPLEMENTED();
 }
 
 void WebGraphicsContext3DCommandBufferImpl::
     rateLimitOffscreenContextCHROMIUM() {
   gl_->RateLimitOffscreenContextCHROMIUM();
@@ skipping 725 matching lines @@
   if (context_lost_callback_) {
     context_lost_callback_->onContextLost();
   }
   RenderViewImpl* renderview =
       web_view_ ? RenderViewImpl::FromWebView(web_view_) : NULL;
   if (renderview)
     renderview->OnViewContextSwapBuffersAborted();
 }
 
 #endif  // defined(ENABLE_GPU)