gpu: Introduce GpuChannelEstablishFactory.

content/browser/compositor/image_transport_factory.h

Index: content/browser/compositor/image_transport_factory.h
diff --git a/content/browser/compositor/image_transport_factory.h b/content/browser/compositor/image_transport_factory.h
index 376e240877549b7e3077e6f27cb472437c618879..aa6720575eacd40c479a2eba7617d95d0f9b2f28 100644
--- a/content/browser/compositor/image_transport_factory.h
+++ b/content/browser/compositor/image_transport_factory.h
@@ -36,6 +36,10 @@ namespace display_compositor {
 class GLHelper;
 }
 
+namespace gpu {
+class GpuChannelEstablishFactory;
+}
+
 namespace content {
 
 // This class provides the interface for creating the support for the
@@ -70,6 +74,9 @@ class CONTENT_EXPORT ImageTransportFactory {
   // (ImageTransportFactoryObserver::OnLostResources is called).
   virtual display_compositor::GLHelper* GetGLHelper() = 0;
 
+  virtual void SetGpuChannelEstablishFactory(
+      gpu::GpuChannelEstablishFactory* factory) = 0;
+
 #if defined(OS_MACOSX)
   // Called with |suspended| as true when the ui::Compositor has been
   // disconnected from an NSView and may be attached to another one. Called