content/blimp: Set up hooks for enabling LTHRemote in the renderer.

content/public/renderer/content_renderer_client.h

Index: content/public/renderer/content_renderer_client.h
diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index 14d85506bf142819d1b5ed5591806ddbeef7ffe0..67aaf70b11cf4867ebb0a63c56687fc3575df0bb 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -58,6 +58,8 @@ struct WebURLError;
 
 namespace cc {
 class ImageSerializationProcessor;
+class RemoteCompositorBridge;
+class RemoteProtoChannel;
 }
 
 namespace gfx {
@@ -276,6 +278,14 @@ class CONTENT_EXPORT ContentRendererClient {
   // Allows an embedder to provide a cc::ImageSerializationProcessor.
   virtual cc::ImageSerializationProcessor* GetImageSerializationProcessor();
 
+  // Allows an embedder to create the cc::RemoteCompositorBridge when using
+  // remote compositing.
+  // The |remote_proto_channel| outlives the RemoteCompositorBridge.
+  virtual std::unique_ptr<cc::RemoteCompositorBridge>
+  CreateRemoteCompositorBridge(
+      cc::RemoteProtoChannel* remote_proto_channel,
+      scoped_refptr<base::SingleThreadTaskRunner> compositor_main_task_runner);
+
   // Allows an embedder to provide a default image decode color space.
   virtual std::unique_ptr<gfx::ICCProfile> GetImageDecodeColorProfile();