remoting/host: Rename Capturer to VideoFrameCapturer.

remoting/host/capturer_helper.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 REMOTING_HOST_CAPTURER_HELPER_H_
-#define REMOTING_HOST_CAPTURER_HELPER_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "base/synchronization/lock.h"
-#include "third_party/skia/include/core/SkRegion.h"
-
-namespace remoting {
-
-// CapturerHelper is intended to be used by an implementation of the Capturer
-// interface. It maintains a thread-safe invalid region, and the size of the
-// most recently captured screen, on behalf of the Capturer that owns it.
-class CapturerHelper {
- public:
-  CapturerHelper();
-  ~CapturerHelper();
-
-  // Clear out the invalid region.
-  void ClearInvalidRegion();
-
-  // Invalidate the specified region.
-  void InvalidateRegion(const SkRegion& invalid_region);
-
-  // Invalidate the entire screen, of a given size.
-  void InvalidateScreen(const SkISize& size);
-
-  // Invalidate the entire screen, using the size of the most recently
-  // captured screen.
-  void InvalidateFullScreen();
-
-  // Swap the given region with the stored invalid region.
-  void SwapInvalidRegion(SkRegion* invalid_region);
-
-  // Access the size of the most recently captured screen.
-  const SkISize& size_most_recent() const;
-  void set_size_most_recent(const SkISize& size);
-
-  // Lossy compression can result in color values leaking between pixels in one
-  // block. If part of a block changes, then unchanged parts of that block can
-  // be changed in the compressed output. So we need to re-render an entire
-  // block whenever part of the block changes.
-  //
-  // If |log_grid_size| is >= 1, then this function makes SwapInvalidRegion
-  // produce an invalid region expanded so that its vertices lie on a grid of
-  // size 2 ^ |log_grid_size|. The expanded region is then clipped to the size
-  // of the most recently captured screen, as previously set by
-  // set_size_most_recent().
-  // If |log_grid_size| is <= 0, then the invalid region is not expanded.
-  void SetLogGridSize(int log_grid_size);
-
-  // Expands a region so that its vertices all lie on a grid.
-  // The grid size must be >= 2, so |log_grid_size| must be >= 1.
-  static scoped_ptr<SkRegion> ExpandToGrid(const SkRegion& region,
-                                           int log_grid_size);
-
- private:
-  // A region that has been manually invalidated (through InvalidateRegion).
-  // These will be returned as dirty_region in the capture data during the next
-  // capture.
-  SkRegion invalid_region_;
-
-  // A lock protecting |invalid_region_| across threads.
-  base::Lock invalid_region_lock_;
-
-  // The size of the most recently captured screen.
-  SkISize size_most_recent_;
-
-  // The log (base 2) of the size of the grid to which the invalid region is
-  // expanded.
-  // If the value is <= 0, then the invalid region is not expanded to a grid.
-  int log_grid_size_;
-
-  DISALLOW_COPY_AND_ASSIGN(CapturerHelper);
-};
-
-}  // namespace remoting
-
-#endif  // REMOTING_HOST_CAPTURER_HELPER_H_