Mac: Partially enable partial swap

content/common/gpu/image_transport_surface_iosurface_mac.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/gpu/image_transport_surface_iosurface_mac.h"
 
 #include "content/common/gpu/gpu_messages.h"
 #include "ui/accelerated_widget_mac/surface_handle_types.h"
 
 namespace content {
@@ skipping 24 matching lines @@
                      int32 value) {
   base::ScopedCFTypeRef<CFNumberRef> number(
       CFNumberCreate(NULL, kCFNumberSInt32Type, &value));
   CFDictionaryAddValue(dictionary, key, number.get());
 }
 
 }  // namespace
 
 IOSurfaceStorageProvider::IOSurfaceStorageProvider(
     ImageTransportSurfaceFBO* transport_surface)
-        : transport_surface_(transport_surface) {}
+        : transport_surface_(transport_surface),
+          frame_scale_factor_(1) {}
 
 IOSurfaceStorageProvider::~IOSurfaceStorageProvider() {
   DCHECK(!io_surface_);
 }
 
 gfx::Size IOSurfaceStorageProvider::GetRoundedSize(gfx::Size size) {
   return gfx::Size(RoundUpSurfaceDimension(size.width()),
                    RoundUpSurfaceDimension(size.height()));
 }
 
@@ skipping 42 matching lines @@
 
   glFlush();
   return true;
 }
 
 void IOSurfaceStorageProvider::FreeColorBufferStorage() {
   io_surface_.reset();
   io_surface_id_ = 0;
 }
 
-void IOSurfaceStorageProvider::SwapBuffers(
-    const gfx::Size& size, float scale_factor) {
+void IOSurfaceStorageProvider::FrameSizeChanged(const gfx::Size& pixel_size,
+                                                float scale_factor) {
+  frame_pixel_size_ = pixel_size;
+  frame_scale_factor_ = scale_factor;
+}
+
+void IOSurfaceStorageProvider::SwapBuffers() {
   // The browser compositor will throttle itself, so we are free to unblock the
   // context immediately. Make sure that the browser is doing its throttling
   // appropriately by ensuring that the previous swap was acknowledged before
   // we get another swap.
   DCHECK(pending_swapped_surfaces_.empty());
   pending_swapped_surfaces_.push_back(io_surface_);
 
   transport_surface_->SendSwapBuffers(
-      ui::SurfaceHandleFromIOSurfaceID(io_surface_id_), size, scale_factor);
+      ui::SurfaceHandleFromIOSurfaceID(io_surface_id_),
+      frame_pixel_size_,
+      frame_scale_factor_);
 }
 
 void IOSurfaceStorageProvider::WillWriteToBackbuffer() {
 }
 
 void IOSurfaceStorageProvider::DiscardBackbuffer() {
 }
 
 void IOSurfaceStorageProvider::SwapBuffersAckedByBrowser(
     bool disable_throttling) {
   DCHECK(!pending_swapped_surfaces_.empty());
   pending_swapped_surfaces_.pop_front();
 }
 
 }  //  namespace content