cc: Add OutputSurface state snapshots.

components/display_compositor/buffer_queue.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 "components/display_compositor/buffer_queue.h"
 
 #include "base/containers/adapters.h"
 #include "base/memory/ptr_util.h"
 #include "build/build_config.h"
 #include "components/display_compositor/gl_helper.h"
@@ skipping 244 matching lines @@
     return nullptr;
   }
 
   allocated_count_++;
   gl_->BindTexture(texture_target_, texture);
   gl_->BindTexImage2DCHROMIUM(texture_target_, id);
   return base::MakeUnique<AllocatedSurface>(this, std::move(buffer), texture,
                                             id, stencil, gfx::Rect(size_));
 }
 
+void BufferQueue::ReadbackDisplayedFramebuffer(
+    SkBitmap* bitmap,
+    const base::Callback<void(bool)>& callback) {
+  if (!displayed_surface_) {
+    callback.Run(false);
+    return;
+  }
+  GLuint texture = gl_helper_->CreateTexture();
+  ScopedTextureBinder<GL_TEXTURE_2D> texture_binder(gl_, texture);
+  gl_->CopyTextureCHROMIUM(displayed_surface_->texture, 0, GL_TEXTURE_2D,
+                           texture, 0, GL_RGBA, GL_UNSIGNED_BYTE, false, false,
+                           false);
+  bitmap->allocN32Pixels(size_.width(), size_.height());
+  gl_helper_->ReadbackTextureAsync(
+      texture, size_, static_cast<unsigned char*>(bitmap->getPixels()),
+      kRGBA_8888_SkColorType, callback);
+  gl_helper_->DeleteTexture(texture);
+}
+
 BufferQueue::AllocatedSurface::AllocatedSurface(
     BufferQueue* buffer_queue,
     std::unique_ptr<gfx::GpuMemoryBuffer> buffer,
     uint32_t texture,
     uint32_t image,
     uint32_t stencil,
     const gfx::Rect& rect)
     : buffer_queue(buffer_queue),
       buffer(buffer.release()),
       texture(texture),
       image(image),
       stencil(stencil),
       damage(rect) {}
 
 BufferQueue::AllocatedSurface::~AllocatedSurface() {
   buffer_queue->FreeSurfaceResources(this);
 }
 
 }  // namespace display_compositor