Implement WebContents.downloadImage() on Java side

content/browser/web_contents/web_contents_android.h

Index: content/browser/web_contents/web_contents_android.h
diff --git a/content/browser/web_contents/web_contents_android.h b/content/browser/web_contents/web_contents_android.h
index 7c890c351b6717febffcb49b22a9ae210ff0cda4..501e67c3dda51e3db8243743d22d884ec94670aa 100644
--- a/content/browser/web_contents/web_contents_android.h
+++ b/content/browser/web_contents/web_contents_android.h
@@ -190,6 +190,14 @@ class CONTENT_EXPORT WebContentsAndroid
     return synchronous_compositor_client_;
   }
 
+  void DownloadImage(JNIEnv* env,
+                     const base::android::JavaParamRef<jobject>& obj,
+                     const base::android::JavaParamRef<jstring>& url,
+                     jboolean is_fav_icon,
+                     jint max_bitmap_size,
+                     jboolean bypass_cache,
+                     const base::android::JavaParamRef<jobject>& jcallback);
+
  private:
   RenderWidgetHostViewAndroid* GetRenderWidgetHostViewAndroid();
 
@@ -199,6 +207,15 @@ class CONTENT_EXPORT WebContentsAndroid
       const SkBitmap& bitmap,
       ReadbackResponse response);
 
+  void OnFinishDownloadImage(
+      base::android::ScopedJavaGlobalRef<jobject>* obj,
+      base::android::ScopedJavaGlobalRef<jobject>* callback,
+      int id,
+      int http_status_code,
+      const GURL& url,
+      const std::vector<SkBitmap>& bitmaps,
+      const std::vector<gfx::Size>& sizes);
+
   WebContentsImpl* web_contents_;
   NavigationControllerAndroid navigation_controller_;
   base::android::ScopedJavaGlobalRef<jobject> obj_;