blimp: Use SwapPromises for readback API.

blimp/client/core/contents/blimp_contents_view_impl.cc

 // Copyright 2016 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 "blimp/client/core/contents/blimp_contents_view_impl.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "blimp/client/core/contents/blimp_contents_impl.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/output/copy_output_result.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace blimp {
 namespace client {
 
+namespace {
+
+void SendReadbackResult(
+    const BlimpContentsView::ReadbackRequestCallback& callback,
+    std::unique_ptr<cc::CopyOutputResult> result) {
+  callback.Run(result->TakeBitmap());
+}
+
+}  // namespace
+
 BlimpContentsViewImpl::BlimpContentsViewImpl(
     BlimpContentsImpl* blimp_contents,
     scoped_refptr<cc::Layer> contents_layer)
     : blimp_contents_(blimp_contents),
       contents_layer_(std::move(contents_layer)),
       weak_ptr_factory_(this) {
   DCHECK(blimp_contents_);
   DCHECK(contents_layer_);
 }
 
 BlimpContentsViewImpl::~BlimpContentsViewImpl() = default;
 
 scoped_refptr<cc::Layer> BlimpContentsViewImpl::GetLayer() {
   return contents_layer_;
 }
 
 void BlimpContentsViewImpl::SetSizeAndScale(const gfx::Size& size,
                                             float device_scale_factor) {
   blimp_contents_->SetSizeAndScale(size, device_scale_factor);
 }
 
 bool BlimpContentsViewImpl::OnTouchEvent(const ui::MotionEvent& motion_event) {
   return blimp_contents_->document_manager()->OnTouchEvent(motion_event);
 }
 
 void BlimpContentsViewImpl::CopyFromCompositingSurface(
     const ReadbackRequestCallback& callback) {
-  blimp_contents_->document_manager()->NotifyWhenDonePendingCommits(
-      base::Bind(&BlimpContentsViewImpl::StartReadbackRequest,
-                 weak_ptr_factory_.GetWeakPtr(), callback));
-}
-
-void BlimpContentsViewImpl::StartReadbackRequest(
-    const ReadbackRequestCallback& callback) {
-  std::unique_ptr<cc::CopyOutputRequest> request =
+  blimp_contents_->document_manager()->RequestCopyOfCompositorOutput(
       cc::CopyOutputRequest::CreateBitmapRequest(
-          base::Bind(&BlimpContentsViewImpl::OnReadbackComplete,
-                     weak_ptr_factory_.GetWeakPtr(), callback));
-  contents_layer_->RequestCopyOfOutput(std::move(request));
-}
-
-void BlimpContentsViewImpl::OnReadbackComplete(
-    const ReadbackRequestCallback& callback,
-    std::unique_ptr<cc::CopyOutputResult> result) {
-  callback.Run(result->TakeBitmap());
+          base::Bind(&SendReadbackResult, callback)),
+      true);
 }
 
 }  // namespace client
 }  // namespace blimp