Add mouse input forwarding to gpu service

content/common/gpu/gpu_channel_manager.cc

Index: content/common/gpu/gpu_channel_manager.cc
diff --git a/content/common/gpu/gpu_channel_manager.cc b/content/common/gpu/gpu_channel_manager.cc
index 69154f0b02475fede824164505546caadb7b6b92..afc2de157b4e921eb48b4149be3aad9d9c63d2d9 100644
--- a/content/common/gpu/gpu_channel_manager.cc
+++ b/content/common/gpu/gpu_channel_manager.cc
@@ -11,6 +11,7 @@
 #include "content/common/gpu/gpu_memory_manager.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/common/message_router.h"
+#include "gpu/command_buffer/common/value_state.h"
 #include "gpu/command_buffer/service/feature_info.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "gpu/command_buffer/service/mailbox_manager_impl.h"
@@ -162,6 +163,7 @@ bool GpuChannelManager::OnMessageReceived(const IPC::Message& msg) {
                         OnCreateViewCommandBuffer)
     IPC_MESSAGE_HANDLER(GpuMsg_DestroyGpuMemoryBuffer, OnDestroyGpuMemoryBuffer)
     IPC_MESSAGE_HANDLER(GpuMsg_LoadedShader, OnLoadedShader)
+    IPC_MESSAGE_HANDLER(GpuMsg_UpdateValueState, OnUpdateValueState)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ -276,6 +278,16 @@ void GpuChannelManager::OnDestroyGpuMemoryBuffer(
   }
 }
 
+void GpuChannelManager::OnUpdateValueState(
+    int client_id, unsigned int target, const gpu::ValueState& state) {
+  // Only pass updated state to the channel corresponding to the
+  // render_widget_host where the event originated.
+  GpuChannelMap::const_iterator iter = gpu_channels_.find(client_id);
+  if (iter != gpu_channels_.end()) {
+    iter->second->HandleUpdateValueState(target, state);

[brianderson, 2014/11/22 01:49:50]

For the security review, it's important to note that the intent of this method
is to only forward the mouse events to the channel that belongs to the Renderer
the input is already going to.

Contexts that belong to other Renderer channels should not have a way to look at
another Renderer's input events, which I believe this patch also guarantees.

+  }
+}
+
 void GpuChannelManager::OnLoadedShader(std::string program_proto) {
   if (program_cache())
     program_cache()->LoadProgram(program_proto);