Use kRenderClientId command line flag when starting a render process

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 57bb2085f61e3f419307f96fb827956bc7ba7206..b5f3d773aac2680e62b90c5b46a243cf43c6e4c0 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -1114,6 +1114,13 @@ void RenderWidget::initializeLayerTreeView() {
     compositor_->SetNeverVisible();
 
   StartCompositor();
+  int32_t client_id = 0;
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(

[Fady Samuel, 2016/10/28 18:14:40]

DCHECK that we have the switch.

[Alex Z., 2016/10/28 18:36:11]

Done.

+          switches::kRendererClientId))
+    client_id =
+        std::stoi(base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(

[Fady Samuel, 2016/10/28 18:14:40]

Use base::StringToInt
https://cs.chromium.org/chromium/src/base/strings/string_number_conversions.h...

[Alex Z., 2016/10/28 18:36:11]

Done.

+            switches::kRendererClientId));
+  compositor_->SetFrameSinkId(cc::FrameSinkId(client_id, routing_id_));
 }
 
 void RenderWidget::WillCloseLayerTreeView() {