Add mouse input forwarding to gpu service

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 9a1d709a2ef00f024c3194de5ec841498afcfc3b..ac93c2ea9dd81c6767cdb11f4e7c03d813a55e37 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -60,6 +60,7 @@
 #include "content/public/common/content_switches.h"
 #include "content/public/common/result_codes.h"
 #include "content/public/common/web_preferences.h"
+#include "gpu/command_buffer/service/gpu_switches.h"
 #include "skia/ext/image_operations.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/WebKit/public/web/WebCompositionUnderline.h"
@@ -855,6 +856,24 @@ void RenderWidgetHostImpl::StopHangMonitorTimeout() {
 
 void RenderWidgetHostImpl::ForwardMouseEvent(const WebMouseEvent& mouse_event) {
   ForwardMouseEventWithLatencyInfo(mouse_event, ui::LatencyInfo());
+  const base::CommandLine& command_line =

[jdduke (slow), 2014/11/18 16:55:30]

I'm wondering if we still want to send this message if the mouse event is
consumed before being forwarded to content, e.g., if consumed by one of the
|mouse_event_callbacks_| or by the TouchEmulator? Would it make sense to move
this logic down into |ForwardMouseEventWithLatencyInfo| below

input_router_->SendMouseEvent(...);

Not sure, I guess if we don't care about double handling maybe it doesn't
matter. 

You might also consider caching the CommandLine query either into a static
boolean or a member variable, as this method can get called with extreme
frequency (though that cost is probably dominated by sending the IPC, still,
don't want to pay the cost when the feature is disabled).

[orglofch, 2014/11/20 02:16:21]

Done.

+      *base::CommandLine::ForCurrentProcess();
+  // Pass mouse state to gpu service if the subscribe uniform
+  // extension is enabled

[Ken Russell (switch to Gerrit), 2014/11/17 23:19:32]

Style nit here and throughout: please add comments with '.'.

[orglofch, 2014/11/20 02:16:21]

Done.

+  if (command_line.HasSwitch(switches::kEnableSubscribeUniformExtension)) {
+    gpu::ValueState state;
+    state.int_value[0] = mouse_event.x;
+    state.int_value[1] = mouse_event.y;
+    GpuProcessHost::SendOnIO(
+#if defined(OS_WIN)

[Ken Russell (switch to Gerrit), 2014/11/17 23:19:32]

This #ifdef is gross. Can you please figure out a better way to factor out the
decision about whether the target GPU process is sandboxed or not?

[orglofch, 2014/11/20 02:16:21]

Done. This was unnecesarry logic, the GPU should be sandboxed unless the client
is collecting Dx diagnostic information.

+      GpuProcessHost::GPU_PROCESS_KIND_UNSANDBOXED,
+#else
+      GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
+#endif
+      CAUSE_FOR_GPU_LAUNCH_NO_LAUNCH,
+      new GpuMsg_UpdateValueState(
+          process_->GetID(), GL_MOUSE_POSITION_CHROMIUM, state));
+  }
 }
 
 void RenderWidgetHostImpl::ForwardMouseEventWithLatencyInfo(