Use kRenderClientId command line flag when starting a render process

content/renderer/render_widget.h

 // 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.
 
 #ifndef CONTENT_RENDERER_RENDER_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 135 matching lines @@
   using RenderWidgetInitializedCallback = void (*)(RenderWidget*);
   static void InstallCreateHook(
       CreateRenderWidgetFunction create_render_widget,
       RenderWidgetInitializedCallback render_widget_initialized_callback);
 
   // Closes a RenderWidget that was created by |CreateForFrame|.
   // TODO(avi): De-virtualize this once RenderViewImpl has-a RenderWidget.
   // https://crbug.com/545684
   virtual void CloseForFrame();
 
+  int32_t client_id() const { return client_id_; }
+
   int32_t routing_id() const { return routing_id_; }
   void SetRoutingID(int32_t routing_id);
 
   CompositorDependencies* compositor_deps() const { return compositor_deps_; }
   virtual blink::WebWidget* GetWebWidget() const;
   const gfx::Size& size() const { return size_; }
   bool is_fullscreen_granted() const { return is_fullscreen_granted_; }
   blink::WebDisplayMode display_mode() const { return display_mode_; }
   bool is_hidden() const { return is_hidden_; }
   // Temporary for debugging purposes...
@@ skipping 427 matching lines @@
   // Tell the browser about the actions permitted for a new touch point.
   void setTouchAction(blink::WebTouchAction touch_action) override;
 
   // Called when value of focused text field gets dirty, e.g. value is modified
   // by script, not by user input.
   void didUpdateTextOfFocusedElementByNonUserInput() override;
 
   // Sends an ACK to the browser process during the next compositor frame.
   void OnWaitNextFrameForTests(int routing_id);
 
+  // Process ID of the browser process. It is used for constructing FrameSinkIds
+  // for the RenderWidgetCompositor
+  int32_t client_id_;
+
   // Routing ID that allows us to communicate to the parent browser process
   // RenderWidgetHost. When MSG_ROUTING_NONE, no messages may be sent.
   int32_t routing_id_;
 
   // Dependencies for initializing a compositor, including flags for optional
   // features.
   CompositorDependencies* const compositor_deps_;
 
   // Use GetWebWidget() instead of using webwidget_internal_ directly.
   // We are responsible for destroying this object via its Close method.
@@ skipping 207 matching lines @@
   // Stores edit commands associated to the next key event.
   // Will be cleared as soon as the next key event is processed.
   EditCommands edit_commands_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_