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 691874df188fe501dbde7e77046dfae03c0d1974..4eaeac73a2043376ce8942d882efea0c5220fe03 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -203,6 +203,7 @@ namespace content {
 RenderWidget::RenderWidget(CompositorDependencies* compositor_deps,
                            blink::WebPopupType popup_type,
                            const ScreenInfo& screen_info,
+                           const cc::FrameSinkId& frame_sink_id,
                            bool swapped_out,
                            bool hidden,
                            bool never_visible)
@@ -234,6 +235,7 @@ RenderWidget::RenderWidget(CompositorDependencies* compositor_deps,
       pending_window_rect_count_(0),
       screen_info_(screen_info),
       device_scale_factor_(screen_info_.device_scale_factor),
+      frame_sink_id_(frame_sink_id),
 #if defined(OS_ANDROID)
       text_field_is_dirty_(false),
 #endif
@@ -285,10 +287,12 @@ void RenderWidget::InstallCreateHook(
 RenderWidget* RenderWidget::Create(int32_t opener_id,
                                    CompositorDependencies* compositor_deps,
                                    blink::WebPopupType popup_type,
-                                   const ScreenInfo& screen_info) {
+                                   const ScreenInfo& screen_info,
+                                   const cc::FrameSinkId& frame_sink_id) {
   DCHECK(opener_id != MSG_ROUTING_NONE);
-  scoped_refptr<RenderWidget> widget(new RenderWidget(
-      compositor_deps, popup_type, screen_info, false, false, false));
+  scoped_refptr<RenderWidget> widget(
+      new RenderWidget(compositor_deps, popup_type, screen_info, frame_sink_id,
+                       false, false, false));
   if (widget->Init(opener_id)) {  // adds reference on success.
     return widget.get();
   }
@@ -301,7 +305,8 @@ RenderWidget* RenderWidget::CreateForFrame(
     bool hidden,
     const ScreenInfo& screen_info,
     CompositorDependencies* compositor_deps,
-    blink::WebLocalFrame* frame) {
+    blink::WebLocalFrame* frame,
+    const cc::FrameSinkId& frame_sink_id) {
   CHECK_NE(routing_id, MSG_ROUTING_NONE);
   // TODO(avi): Before RenderViewImpl has-a RenderWidget, the browser passes the
   // same routing ID for both the view routing ID and the main frame widget
@@ -315,9 +320,10 @@ RenderWidget* RenderWidget::CreateForFrame(
   scoped_refptr<RenderWidget> widget(
       g_create_render_widget
           ? g_create_render_widget(compositor_deps, blink::WebPopupTypeNone,
-                                   screen_info, false, hidden, false)
+                                   screen_info, frame_sink_id, false, hidden,

[Fady Samuel, 2016/10/26 15:00:18]

This isn't right. Each RenderWidget should share the same client_id but get a
different sink ID equal to the routing ID.

I think we should tell a renderer process its client ID via flag when the
process is created, and when a RenderWidget gets a routing ID (via SetRoutingID)
it should get its sink ID.

+                                   false)
           : new RenderWidget(compositor_deps, blink::WebPopupTypeNone,
-                             screen_info, false, hidden, false));
+                             screen_info, frame_sink_id, false, hidden, false));
   widget->SetRoutingID(routing_id);
   widget->for_oopif_ = true;
   // DoInit increments the reference count on |widget|, keeping it alive after