Mac: Correctly show/hide compositor on navigations.

chrome/renderer/webgles2context_impl.cc

 // Copyright (c) 2010 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 "chrome/renderer/webgles2context_impl.h"
 
 #include "chrome/renderer/gpu_channel_host.h"
 #include "chrome/renderer/render_thread.h"
 #include "chrome/renderer/render_view.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebView.h"
 
 
-WebGLES2ContextImpl::WebGLES2ContextImpl() : context_(NULL) {
+WebGLES2ContextImpl::WebGLES2ContextImpl()
+    : context_(NULL)
+#if defined(OS_MACOSX)
+    , plugin_handle_(gfx::kNullPluginWindow)
+    , web_view_(NULL)
+#endif
+    {
 }
 
 WebGLES2ContextImpl::~WebGLES2ContextImpl() {
   destroy();
 }
 
 // TODO(vangelis): Remove once the method is removed from the WebGLES2Context.
 bool WebGLES2ContextImpl::initialize(WebKit::WebView* web_view) {
     return initialize(web_view, NULL);
 }
@@ skipping 16 matching lines @@
   // into the window used by the WebView, otherwise create an offscreen
   // context.
   if (web_view) {
     RenderView* renderview = RenderView::FromWebView(web_view);
     if (!renderview)
       return false;
     gfx::NativeViewId view_id;
 #if !defined(OS_MACOSX)
     view_id = renderview->host_window();
 #else
-    view_id = static_cast<gfx::NativeViewId>(
-        renderview->AllocateFakePluginWindowHandle(true, true));
+    plugin_handle_ = renderview->AllocateFakePluginWindowHandle(true, true);
+    web_view_ = web_view;
+    view_id = static_cast<gfx::NativeViewId>(plugin_handle_);
 #endif
     context_ = ggl::CreateViewContext(
         host, view_id,
         renderview->routing_id());
   } else {
     ggl::Context* parent_context = NULL;
 
     if (parent) {
       WebGLES2ContextImpl* parent_context_impl =
           static_cast<WebGLES2ContextImpl*>(parent);
       parent_context = parent_context_impl->context();
       DCHECK(parent_context);
     }
     context_ = ggl::CreateOffscreenContext(host, parent_context,
                                            gfx::Size(1, 1));
   }
 
   return (context_ != NULL);
 }
 
 bool WebGLES2ContextImpl::makeCurrent() {
   return ggl::MakeCurrent(context_);
 }
 
 bool WebGLES2ContextImpl::destroy() {
+#if defined(OS_MACOSX)
+  RenderView* renderview = RenderView::FromWebView(web_view_);
+  DCHECK(plugin_handle_ == gfx::kNullPluginWindow || renderview);
+  if (plugin_handle_ != gfx::kNullPluginWindow && renderview)
+    renderview->DestroyFakePluginWindowHandle(plugin_handle_);
+  plugin_handle_ = gfx::kNullPluginWindow;
+#endif
   return ggl::DestroyContext(context_);
 }
 
 bool WebGLES2ContextImpl::swapBuffers() {
   return ggl::SwapBuffers(context_);
 }
 
 void WebGLES2ContextImpl::resizeOffscreenContent(const WebKit::WebSize& size) {
   ggl::ResizeOffscreenContext(context_, size);
 }
 
 unsigned WebGLES2ContextImpl::getOffscreenContentParentTextureId() {
   return ggl::GetParentTextureId(context_);
 }
 
 #if defined(OS_MACOSX)
 void WebGLES2ContextImpl::resizeOnscreenContent(const WebKit::WebSize& size) {
   ggl::ResizeOnscreenContext(context_, size);
 }
 #endif
 
 #endif  // defined(ENABLE_GPU)