[Android WebView] Implement the capture picture API.

android_webview/browser/renderer_host/aw_render_view_host_ext.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 ANDROID_WEBVIEW_BROWSER_RENDER_HOST_RENDER_VIEW_HOST_EXT_H_
 #define ANDROID_WEBVIEW_BROWSER_RENDER_HOST_RENDER_VIEW_HOST_EXT_H_
 
 #include "content/public/browser/web_contents_observer.h"
 
 #include "android_webview/common/aw_hit_test_data.h"
@@ skipping 32 matching lines @@
   void RequestNewHitTestDataAt(int view_x, int view_y);
 
   // Optimization to avoid unnecessary Java object creation on hit test.
   bool HasNewHitTestData() const;
   void MarkHitTestDataRead();
 
   // Return |last_hit_test_data_|. Note that this is unavoidably racy;
   // the corresponding public WebView API is as well.
   const AwHitTestData& GetLastHitTestData() const;
 
+  // Enables updating picture piles on every new frame.
+  // OnPictureUpdated is called when a new picture is available,
+  // stored by renderer id in RendererPictureMap.
+  void EnableCapturePictureCallback(bool enabled);
+
+  // Captures the latest available picture pile synchronously.
+  void CapturePictureSync();
+
  private:
   // content::WebContentsObserver implementation.
   virtual void RenderViewGone(base::TerminationStatus status) OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   void OnDocumentHasImagesResponse(int msg_id, bool has_images);
   void OnUpdateHitTestData(const AwHitTestData& hit_test_data);
   void OnPictureUpdated();
 
   std::map<int, DocumentHasImagesResult> pending_document_has_images_requests_;
 
   // Master copy of hit test data on the browser side. This is updated
   // as a result of DoHitTest called explicitly or when the FocusedNodeChanged
   // is called in AwRenderViewExt.
   AwHitTestData last_hit_test_data_;
 
   bool has_new_hit_test_data_;
 
   Client* client_;
 
   DISALLOW_COPY_AND_ASSIGN(AwRenderViewHostExt);
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_RENDER_HOST_RENDER_VIEW_HOST_EXT_H_