Fix race conditions in window snapshot code.

content/renderer/render_thread_impl.cc

 // Copyright (c) 2012 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.
 
 #include "content/renderer/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <vector>
@@ skipping 396 matching lines @@
   // Note that under Linux, the media library will normally already have
   // been initialized by the Zygote before this instance became a Renderer.
   base::FilePath media_path;
   PathService::Get(DIR_MEDIA_LIBS, &media_path);
   if (!media_path.empty())
     media::InitializeMediaLibrary(media_path);
 
   memory_pressure_listener_.reset(new base::MemoryPressureListener(
       base::Bind(&RenderThreadImpl::OnMemoryPressure, base::Unretained(this))));
 
+  renderer_process_id_ = base::kNullProcessId;
+
   TRACE_EVENT_END_ETW("RenderThreadImpl::Init", 0, "");
 }
 
 RenderThreadImpl::~RenderThreadImpl() {
 }
 
 void RenderThreadImpl::Shutdown() {
   FOR_EACH_OBSERVER(
       RenderProcessObserver, observers_, OnRenderProcessShutdown());
 
@@ skipping 683 matching lines @@
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RenderThreadImpl, msg)
     IPC_MESSAGE_HANDLER(ViewMsg_SetZoomLevelForCurrentURL,
                         OnSetZoomLevelForCurrentURL)
     // TODO(port): removed from render_messages_internal.h;
     // is there a new non-windows message I should add here?
     IPC_MESSAGE_HANDLER(ViewMsg_New, OnCreateNewView)
     IPC_MESSAGE_HANDLER(ViewMsg_PurgePluginListCache, OnPurgePluginListCache)
     IPC_MESSAGE_HANDLER(ViewMsg_NetworkStateChanged, OnNetworkStateChanged)
     IPC_MESSAGE_HANDLER(ViewMsg_TempCrashWithData, OnTempCrashWithData)
+    IPC_MESSAGE_HANDLER(ViewMsg_SetRendererProcessID, OnSetRendererProcessID)
     IPC_MESSAGE_HANDLER(ViewMsg_SetWebKitSharedTimersSuspended,
                         OnSetWebKitSharedTimersSuspended)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void RenderThreadImpl::OnCreateNewView(const ViewMsg_New_Params& params) {
   EnsureWebKitInitialized();
   // When bringing in render_view, also bring in webkit's glue and jsbindings.
@@ skipping 117 matching lines @@
 void RenderThreadImpl::OnNetworkStateChanged(bool online) {
   EnsureWebKitInitialized();
   WebNetworkStateNotifier::setOnLine(online);
 }
 
 void RenderThreadImpl::OnTempCrashWithData(const GURL& data) {
   GetContentClient()->SetActiveURL(data);
   CHECK(false);
 }
 
+void RenderThreadImpl::OnSetRendererProcessID(int64 process_id) {
+  renderer_process_id_ = static_cast<base::ProcessId>(process_id);
+}
+
 void RenderThreadImpl::OnSetWebKitSharedTimersSuspended(bool suspend) {
   ToggleWebKitSharedTimer(suspend);
 }
 
 void RenderThreadImpl::OnMemoryPressure(
     base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
   base::allocator::ReleaseFreeMemory();
 
   if (memory_pressure_level ==
       base::MemoryPressureListener::MEMORY_PRESSURE_CRITICAL) {
@@ skipping 39 matching lines @@
                                                     new_touchscreen);
 
 }
 
 void RenderThreadImpl::SampleGamepads(WebKit::WebGamepads* data) {
   if (!gamepad_shared_memory_reader_)
     gamepad_shared_memory_reader_.reset(new GamepadSharedMemoryReader);
   gamepad_shared_memory_reader_->SampleGamepads(*data);
 }
 
+base::ProcessId RenderThreadImpl::renderer_process_id() const {
+  return renderer_process_id_;
+}
+
 }  // namespace content