cc: Add asynchronous setPixel interface.

cc/resource_provider.h

Index: cc/resource_provider.h
diff --git a/cc/resource_provider.h b/cc/resource_provider.h
index e75cda6e56807310ae874131492fed7a03a04519..60a7a21f4ad8057e6914c0db5d7cd91d8711015c 100644
--- a/cc/resource_provider.h
+++ b/cc/resource_provider.h
@@ -197,6 +197,16 @@ public:
         DISALLOW_COPY_AND_ASSIGN(ScopedWriteLockSoftware);
     };
 
+    // This set of functions can be used to asynchronously set pixel values
+    // for a resource.
+    void acquirePixelBuffer(ResourceId id);
+    void releasePixelBuffer(ResourceId id);
+    uint8_t* mapPixelBuffer(ResourceId id);
+    void unmapPixelBuffer(ResourceId id);
+    void beginSetPixels(ResourceId id);
+    bool didSetPixelsComplete(ResourceId id);
+    void abortSetPixels(ResourceId id);
+
 private:
     struct Resource {
         Resource();
@@ -204,8 +214,13 @@ private:
         Resource(uint8_t* pixels, int pool, const gfx::Size& size, GLenum format);
 
         unsigned glId;
+        // Pixel buffer used for asynchronous set pixels.
+        unsigned glPixelBufferId;
+        // Query used to determine when asynchronous set pixels complete.
+        unsigned glUploadQueryId;
         Mailbox mailbox;
         uint8_t* pixels;
+        uint8_t* pixelBuffer;
         int pool;
         int lockForReadCount;
         bool lockedForWrite;