Initialize CompositorDependencies in RenderWidget's constructor.

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index c80ea8bd9f576fd0428d3d331dd3dd0ea6d10350..68715b008305e259a5f1409fddcaf14973a8c4df 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -357,7 +357,8 @@ class CONTENT_EXPORT RenderWidget
     NO_RESIZE_ACK,
   };
 
-  RenderWidget(blink::WebPopupType popup_type,
+  RenderWidget(CompositorDependencies* compositor_deps,
+               blink::WebPopupType popup_type,
                const blink::WebScreenInfo& screen_info,
                bool swapped_out,
                bool hidden,
@@ -373,11 +374,10 @@ class CONTENT_EXPORT RenderWidget
 
   // Initializes this view with the given opener.  CompleteInit must be called
   // later.
-  bool Init(int32 opener_id, CompositorDependencies* compositor_deps);
+  bool Init(int32 opener_id);
 
   // Called by Init and subclasses to perform initialization.
   bool DoInit(int32 opener_id,
-              CompositorDependencies* compositor_deps,
               blink::WebWidget* web_widget,
               IPC::SyncMessage* create_widget_message);
 
@@ -603,7 +603,7 @@ class CONTENT_EXPORT RenderWidget
 
   // Dependencies for initializing a compositor, including flags for optional
   // features.
-  CompositorDependencies* compositor_deps_;
+  CompositorDependencies* const compositor_deps_;
 
   // We are responsible for destroying this object via its Close method.
   // May be NULL when the window is closing.