Make WindowReachedScreen support async readback

ui/snapshot/snapshot_aura.cc

 // 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.
 
 #include "ui/snapshot/snapshot.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/safe_numerics.h"
@@ skipping 159 matching lines @@
 
 bool GrabViewSnapshot(gfx::NativeView view,
                       std::vector<unsigned char>* png_representation,
                       const gfx::Rect& snapshot_bounds) {
   return GrabWindowSnapshot(view, png_representation, snapshot_bounds);
 }
 
 bool GrabWindowSnapshot(gfx::NativeWindow window,
                         std::vector<unsigned char>* png_representation,
                         const gfx::Rect& snapshot_bounds) {
-  gfx::Rect read_pixels_bounds_in_pixel =
-      GetTargetBoundsFromWindow(window, snapshot_bounds);
-
-  ui::Compositor* compositor = window->layer()->GetCompositor();
-  SkBitmap bitmap;
-  if (!compositor->ReadPixels(&bitmap, read_pixels_bounds_in_pixel))
-    return false;
-
-  gfx::Display display =
-      gfx::Screen::GetScreenFor(window)->GetDisplayNearestWindow(window);
-  RotateBitmap(&bitmap, display.rotation());
-
-  unsigned char* pixels = reinterpret_cast<unsigned char*>(
-      bitmap.pixelRef()->pixels());
-  return gfx::PNGCodec::Encode(
-      pixels, gfx::PNGCodec::FORMAT_BGRA,
-      gfx::Size(bitmap.width(), bitmap.height()),
-      base::checked_numeric_cast<int>(bitmap.rowBytes()),
-      true, std::vector<gfx::PNGCodec::Comment>(),
-      png_representation);
+  // Not supported in Aura.  Callers should fall back to the async version.
+  return false;
 }
 
 void MakeAsyncCopyRequest(
     gfx::NativeWindow window,
     const gfx::Rect& source_rect,
     const cc::CopyOutputRequest::CopyOutputRequestCallback& callback) {
   scoped_ptr<cc::CopyOutputRequest> request =
       cc::CopyOutputRequest::CreateBitmapRequest(callback);
   request->set_area(ui::ConvertRectToPixel(window->layer(), source_rect));
   window->layer()->RequestCopyOfOutput(request.Pass());
@@ skipping 44 matching lines @@
                                         .rotation();
   MakeAsyncCopyRequest(window,
                        source_rect,
                        base::Bind(&ScaleRotateAndEncodeCopyOutputResult,
                                   callback,
                                   target_size,
                                   rotation,
                                   background_task_runner));
 }
 
+void GrabViewSnapshotAsync(
+    gfx::NativeView view,
+    const gfx::Rect& source_rect,
+    scoped_refptr<base::TaskRunner> background_task_runner,
+    const GrabWindowSnapshotAsyncPNGCallback& callback) {
+  GrabWindowSnapshotAsync(view, source_rect, background_task_runner, callback);
+}
+
+
 }  // namespace ui