Make ui::Snapshot asynchronous on Android, remove CompositeAndReadback.

ui/snapshot/snapshot_aura.cc

Index: ui/snapshot/snapshot_aura.cc
diff --git a/ui/snapshot/snapshot_aura.cc b/ui/snapshot/snapshot_aura.cc
index a360b87e116ff5f75bd5af4516976264cf5fea9d..fc7e6e7271d55c6f6ebfdb7c2669eb517d0da7d2 100644
--- a/ui/snapshot/snapshot_aura.cc
+++ b/ui/snapshot/snapshot_aura.cc
@@ -6,109 +6,17 @@
 
 #include "base/bind.h"
 #include "base/callback.h"
-#include "base/logging.h"
-#include "base/numerics/safe_conversions.h"
 #include "base/task_runner_util.h"
 #include "cc/output/copy_output_request.h"
-#include "cc/output/copy_output_result.h"
-#include "skia/ext/image_operations.h"
 #include "third_party/skia/include/core/SkBitmap.h"
-#include "third_party/skia/include/core/SkPixelRef.h"
 #include "ui/aura/window.h"
-#include "ui/aura/window_event_dispatcher.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/dip_util.h"
 #include "ui/compositor/layer.h"
-#include "ui/gfx/codec/png_codec.h"
-#include "ui/gfx/display.h"
-#include "ui/gfx/image/image.h"
-#include "ui/gfx/image/image_skia.h"
-#include "ui/gfx/rect.h"
-#include "ui/gfx/rect_conversions.h"
-#include "ui/gfx/rect_f.h"
-#include "ui/gfx/screen.h"
-#include "ui/gfx/skbitmap_operations.h"
-#include "ui/gfx/transform.h"
+#include "ui/snapshot/snapshot_async.h"
 
 namespace ui {
 
-namespace {
-
-void OnFrameScalingFinished(
-    const GrabWindowSnapshotAsyncCallback& callback,
-    const SkBitmap& scaled_bitmap) {
-  callback.Run(gfx::Image(gfx::ImageSkia::CreateFrom1xBitmap(scaled_bitmap)));
-}
-
-SkBitmap ScaleBitmap(const SkBitmap& input_bitmap,
-                     const gfx::Size& target_size) {
-  return skia::ImageOperations::Resize(
-      input_bitmap,
-      skia::ImageOperations::RESIZE_GOOD,
-      target_size.width(),
-      target_size.height(),
-      static_cast<SkBitmap::Allocator*>(NULL));
-}
-
-scoped_refptr<base::RefCountedBytes> EncodeBitmap(const SkBitmap& bitmap) {
-  scoped_refptr<base::RefCountedBytes> png_data(new base::RefCountedBytes);
-  unsigned char* pixels =
-      reinterpret_cast<unsigned char*>(bitmap.pixelRef()->pixels());
-  if (!gfx::PNGCodec::Encode(pixels,
-                             gfx::PNGCodec::FORMAT_BGRA,
-                             gfx::Size(bitmap.width(), bitmap.height()),
-                             base::checked_cast<int>(bitmap.rowBytes()),
-                             true,
-                             std::vector<gfx::PNGCodec::Comment>(),
-                             &png_data->data())) {
-    return scoped_refptr<base::RefCountedBytes>();
-  }
-  return png_data;
-}
-
-void ScaleCopyOutputResult(
-    const GrabWindowSnapshotAsyncCallback& callback,
-    const gfx::Size& target_size,
-    scoped_refptr<base::TaskRunner> background_task_runner,
-    scoped_ptr<cc::CopyOutputResult> result) {
-  if (result->IsEmpty()) {
-    callback.Run(gfx::Image());
-    return;
-  }
-
-  // TODO(sergeyu): Potentially images can be scaled on GPU before reading it
-  // from GPU. Image scaling is implemented in content::GlHelper, but it's can't
-  // be used here because it's not in content/public. Move the scaling code
-  // somewhere so that it can be reused here.
-  base::PostTaskAndReplyWithResult(
-      background_task_runner,
-      FROM_HERE,
-      base::Bind(ScaleBitmap, *result->TakeBitmap(), target_size),
-      base::Bind(&OnFrameScalingFinished, callback));
-}
-
-void EncodeCopyOutputResult(
-    const GrabWindowSnapshotAsyncPNGCallback& callback,
-    scoped_refptr<base::TaskRunner> background_task_runner,
-    scoped_ptr<cc::CopyOutputResult> result) {
-  if (result->IsEmpty()) {
-    callback.Run(scoped_refptr<base::RefCountedBytes>());
-    return;
-  }
-
-  // TODO(sergeyu): Potentially images can be scaled on GPU before reading it
-  // from GPU. Image scaling is implemented in content::GlHelper, but it's can't
-  // be used here because it's not in content/public. Move the scaling code
-  // somewhere so that it can be reused here.
-  base::PostTaskAndReplyWithResult(background_task_runner,
-                                   FROM_HERE,
-                                   base::Bind(EncodeBitmap,
-                                              *result->TakeBitmap()),
-                                   callback);
-}
-
-}  // namespace
-
 bool GrabViewSnapshot(gfx::NativeView view,
                       std::vector<unsigned char>* png_representation,
                       const gfx::Rect& snapshot_bounds) {
@@ -122,7 +30,7 @@ bool GrabWindowSnapshot(gfx::NativeWindow window,
   return false;
 }
 
-void MakeAsyncCopyRequest(
+static void MakeAsyncCopyRequest(
     gfx::NativeWindow window,
     const gfx::Rect& source_rect,
     const cc::CopyOutputRequest::CopyOutputRequestCallback& callback) {
@@ -140,7 +48,7 @@ void GrabWindowSnapshotAndScaleAsync(
     const GrabWindowSnapshotAsyncCallback& callback) {
   MakeAsyncCopyRequest(window,
                        source_rect,
-                       base::Bind(&ScaleCopyOutputResult,
+                       base::Bind(&SnapshotAsync::ScaleCopyOutputResult,
                                   callback,
                                   target_size,
                                   background_task_runner));
@@ -153,7 +61,7 @@ void GrabWindowSnapshotAsync(
     const GrabWindowSnapshotAsyncPNGCallback& callback) {
   MakeAsyncCopyRequest(window,
                        source_rect,
-                       base::Bind(&EncodeCopyOutputResult,
+                       base::Bind(&SnapshotAsync::EncodeCopyOutputResult,
                                   callback,
                                   background_task_runner));
 }