Fix set_area sizes for RequestCopyOfOutput, and related tests.

ui/snapshot/snapshot.h

 // Copyright (c) 2012 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.
 
 #ifndef UI_SNAPSHOT_SNAPSHOT_H_
 #define UI_SNAPSHOT_SNAPSHOT_H_
 
 #include <vector>
 
 #include "base/callback_forward.h"
@@ skipping 23 matching lines @@
 SNAPSHOT_EXPORT bool GrabWindowSnapshot(
     gfx::NativeWindow window,
     std::vector<unsigned char>* png_representation,
     const gfx::Rect& snapshot_bounds);
 
 SNAPSHOT_EXPORT bool GrabViewSnapshot(
     gfx::NativeView view,
     std::vector<unsigned char>* png_representation,
     const gfx::Rect& snapshot_bounds);
 
+
+// These functions take a snapshot of |source_rect|, specified in layer space
+// coordinates (DIP for desktop, physical pixels for Android), and scale the
+// snapshot to |target_size| (in physical pixels), asynchronously.
 typedef base::Callback<void(const gfx::Image& snapshot)>
     GrabWindowSnapshotAsyncCallback;
-// GrabWindowSnapshotAndScaleAsync() copies snapshot of |source_rect| from
-// window and scales it to |target_size| asynchronously.
 SNAPSHOT_EXPORT void GrabWindowSnapshotAndScaleAsync(
     gfx::NativeWindow window,
     const gfx::Rect& source_rect,
     const gfx::Size& target_size,
     scoped_refptr<base::TaskRunner> background_task_runner,
     const GrabWindowSnapshotAsyncCallback& callback);
 
 typedef base::Callback<void(scoped_refptr<base::RefCountedBytes> png_data)>
     GrabWindowSnapshotAsyncPNGCallback;
 SNAPSHOT_EXPORT void GrabWindowSnapshotAsync(
     gfx::NativeWindow window,
     const gfx::Rect& source_rect,
     scoped_refptr<base::TaskRunner> background_task_runner,
     const GrabWindowSnapshotAsyncPNGCallback& callback);
 SNAPSHOT_EXPORT void GrabViewSnapshotAsync(
     gfx::NativeView view,
     const gfx::Rect& source_rect,
     scoped_refptr<base::TaskRunner> background_task_runner,
     const GrabWindowSnapshotAsyncPNGCallback& callback);
 
 }  // namespace ui
 
 #endif  // UI_SNAPSHOT_SNAPSHOT_H_