[Android] Open up API in jni bridge to fetch images from tab

chrome/browser/enhanced_bookmarks/android/enhanced_bookmarks_bridge.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 CHROME_BROWSER_ENHANCED_BOOKMARKS_ANDROID_ENHANCED_BOOKMARKS_BRIDGE_H_
 #define CHROME_BROWSER_ENHANCED_BOOKMARKS_ANDROID_ENHANCED_BOOKMARKS_BRIDGE_H_
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_weak_ref.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "components/enhanced_bookmarks/bookmark_server_search_service.h"
 #include "components/enhanced_bookmarks/bookmark_server_service.h"
 
 namespace enhanced_bookmarks {
 
 class BookmarkServerClusterService;
-class BookmarkImageService;
+class BookmarkImageServiceAndroid;
 
 namespace android {
 
 class EnhancedBookmarksBridge : public BookmarkServerServiceObserver {
  public:
   EnhancedBookmarksBridge(JNIEnv* env, jobject obj, Profile* profile);
   ~EnhancedBookmarksBridge() override;
   void Destroy(JNIEnv*, jobject);
 
   void SalientImageForUrl(JNIEnv* env,
                           jobject obj,
                           jstring j_url,
                           jobject j_callback);
 
+  void FetchImageForTab(JNIEnv* env, jobject obj, jobject j_tab);
+
   base::android::ScopedJavaLocalRef<jstring> GetBookmarkDescription(
       JNIEnv* env,
       jobject obj,
       jlong id,
       jint type);
   void SetBookmarkDescription(JNIEnv* env,
                               jobject obj,
                               jlong id,
                               jint type,
                               jstring description);
@@ skipping 37 matching lines @@
   // BookmarkServerServiceObserver
   // Called on changes to cluster data or search results are returned.
   void OnChange(BookmarkServerService* service) override;
 
  private:
   bool IsEditable(const bookmarks::BookmarkNode* node) const;
 
   JavaObjectWeakGlobalRef weak_java_ref_;
   EnhancedBookmarkModel* enhanced_bookmark_model_;  // weak
   BookmarkServerClusterService* cluster_service_;   // weak
-  BookmarkImageService* bookmark_image_service_;    // weak
+  BookmarkImageServiceAndroid* bookmark_image_service_;    // weak
   scoped_ptr<BookmarkServerSearchService> search_service_;
   Profile* profile_;                       // weak
   DISALLOW_COPY_AND_ASSIGN(EnhancedBookmarksBridge);
 };
 
 bool RegisterEnhancedBookmarksBridge(JNIEnv* env);
 
 }  // namespace android
 }  // namespace enhanced_bookmarks
 
 #endif  // CHROME_BROWSER_ENHANCED_BOOKMARKS_ANDROID_ENHANCED_BOOKMARKS_BRIDGE_H_