DevTools: optimize screencast for slower devices.

content/browser/devtools/protocol/page_handler.h

 // 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.
 
 #ifndef CONTENT_BROWSER_DEVTOOLS_PROTOCOL_PAGE_HANDLER_H_
 #define CONTENT_BROWSER_DEVTOOLS_PROTOCOL_PAGE_HANDLER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 47 matching lines @@
                                 NavigationEntries* entries);
 
   Response NavigateToHistoryEntry(int entry_id);
 
   Response CaptureScreenshot(DevToolsCommandId command_id);
 
   Response CanScreencast(bool* result);
   Response StartScreencast(const std::string* format,
                            const int* quality,
                            const int* max_width,
-                           const int* max_height);
+                           const int* max_height,
+                           const int* every_nth_frame);
   Response StopScreencast();
-  Response ScreencastFrameAck(int frame_number);
+  Response ScreencastFrameAck();
 
   Response HandleJavaScriptDialog(bool accept, const std::string* prompt_text);
 
   Response QueryUsageAndQuota(DevToolsCommandId command_id,
                               const std::string& security_origin);
 
   Response SetColorPickerEnabled(bool enabled);
 
  private:
   WebContentsImpl* GetWebContents();
@@ skipping 18 matching lines @@
                const NotificationSource& source,
                const NotificationDetails& details) override;
 
   bool enabled_;
 
   bool screencast_enabled_;
   std::string screencast_format_;
   int screencast_quality_;
   int screencast_max_width_;
   int screencast_max_height_;
+  int capture_every_nth_frame_;
   int capture_retry_count_;
   bool has_compositor_frame_metadata_;
   cc::CompositorFrameMetadata next_compositor_frame_metadata_;
   cc::CompositorFrameMetadata last_compositor_frame_metadata_;
-  int screencast_frame_sent_;
-  int screencast_frame_acked_;
-  bool processing_screencast_frame_;
+  int frame_counter_;
+  int frames_in_flight_;
 
   scoped_ptr<ColorPicker> color_picker_;
 
   RenderFrameHostImpl* host_;
   scoped_ptr<Client> client_;
   NotificationRegistrar registrar_;
   base::WeakPtrFactory<PageHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PageHandler);
 };
 
 }  // namespace page
 }  // namespace devtools
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_PROTOCOL_PAGE_HANDLER_H_