gpu: Add async pixel transfer interface, stub and tests.

gpu/command_buffer/service/texture_manager.h

Index: gpu/command_buffer/service/texture_manager.h
diff --git a/gpu/command_buffer/service/texture_manager.h b/gpu/command_buffer/service/texture_manager.h
index 8c3100b4a74faebb0c044a1d433ed1ae5d459e76..a4c7b675c74be6a600f7bd2b61e482fe4d055b36 100644
--- a/gpu/command_buffer/service/texture_manager.h
+++ b/gpu/command_buffer/service/texture_manager.h
@@ -15,6 +15,7 @@
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/command_buffer/service/memory_tracking.h"
 #include "gpu/gpu_export.h"
+#include "ui/gl/async_pixel_transfer_delegate.h"
 #include "ui/gl/gl_image.h"
 
 namespace gpu {
@@ -174,6 +175,17 @@ class GPU_EXPORT TextureManager {
       return stream_texture_;
     }
 
+    gfx::AsyncPixelTransferState* GetAsyncTransferState() const {
+      return async_transfer_state_.get();
+    }
+    void SetAsyncTransferState(gfx::AsyncPixelTransferState* state) {
+      async_transfer_state_ = state;
+    }
+    bool AsyncTransferIsInProgress() {
+      return async_transfer_state_ &&
+          async_transfer_state_->TransferIsInProgress();
+    }
+
     void SetImmutable(bool immutable) {
       immutable_ = immutable;
     }
@@ -185,6 +197,11 @@ class GPU_EXPORT TextureManager {
     // Whether a particular level/face is cleared.
     bool IsLevelCleared(GLenum target, GLint level);
 
+    // Whether the texture has been defined
+    bool IsDefined() {
+      return estimated_size() > 0;
+    }
+
    private:
     friend class TextureManager;
     friend class base::RefCounted<TextureInfo>;
@@ -341,6 +358,9 @@ class GPU_EXPORT TextureManager {
     // Whether this is a special streaming texture.
     bool stream_texture_;
 
+    // State to facilitate async transfers on this texture.
+    scoped_refptr<gfx::AsyncPixelTransferState> async_transfer_state_;
+
     // Whether the texture is immutable and no further changes to the format
     // or dimensions of the texture object can be made.
     bool immutable_;