Plumb overlay processing into DirectRenderer.

cc/resources/resource_provider.h

Index: cc/resources/resource_provider.h
diff --git a/cc/resources/resource_provider.h b/cc/resources/resource_provider.h
index 056ce2fc6f60c99b59373e73cefdefa60c0128d3..b54c04109c266ab59c8c61d853aaaf29c7503f82 100644
--- a/cc/resources/resource_provider.h
+++ b/cc/resources/resource_provider.h
@@ -305,6 +305,22 @@ class CC_EXPORT ResourceProvider {
     DISALLOW_COPY_AND_ASSIGN(ScopedWriteLockSoftware);
   };
 
+  class CC_EXPORT ScopedExportLock {
+   public:
+    ScopedExportLock(ResourceProvider* resource_provider,
+                     ResourceProvider::ResourceId resource_id);
+    virtual ~ScopedExportLock();
+
+    const gpu::Mailbox& GetMailbox() const;
+
+   protected:
+    ResourceProvider* resource_provider_;
+    ResourceProvider::ResourceId resource_id_;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(ScopedExportLock);
+  };
+
   class Fence : public base::RefCounted<Fence> {
    public:
     Fence() {}
@@ -572,6 +588,8 @@ class CC_EXPORT ResourceProvider {
   void UnlockForRead(ResourceId id);
   const Resource* LockForWrite(ResourceId id);
   void UnlockForWrite(ResourceId id);
+  const Resource* LockForExport(ResourceId id);
+  void UnlockForExport(ResourceId id);
   static void PopulateSkBitmapWithResource(SkBitmap* sk_bitmap,
                                            const Resource* resource);