Replace image_messages.h with Mojo service

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index d34b4ef33c89eddbfbf4800ba3da7830b9d375e3..b6e563a51d63e58d624e8b17b15aa077195b1f8b 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -20,9 +20,11 @@
 #include "content/common/content_export.h"
 #include "content/common/frame_message_enums.h"
 #include "content/common/frame_replication_state.h"
+#include "content/common/image_downloader/image_downloader.mojom.h"
 #include "content/common/mojo/service_registry_impl.h"
 #include "content/common/navigation_params.h"
 #include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
 #include "content/public/common/javascript_message_type.h"
 #include "net/http/http_response_headers.h"
 #include "third_party/WebKit/public/web/WebTextDirection.h"
@@ -445,6 +447,13 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // addition, its associated RenderWidgetHost has to be focused.
   bool IsFocused();
 
+  // Download image API called by web_contents.

[nasko, 2015/07/02 08:41:07]

No need to add specifics as to who calls this method, it can be anyone in the
future, so this type of comment will get stale/incorrect.

[leonhsl(Using Gerrit), 2015/07/06 02:15:25]

Done.

+  int DownloadImage(const GURL& url,
+                    bool is_favicon,
+                    uint32_t max_bitmap_size,
+                    bool bypass_cache,
+                    const WebContents::ImageDownloadCallback& callback);
+
  protected:
   friend class RenderFrameHostFactory;
 
@@ -735,6 +744,9 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // The frame's Mojo Shell service.
   scoped_ptr<FrameMojoShell> frame_mojo_shell_;
 
+  // Holder of Mojo connection with ImageDownloader service in RenderFrame.
+  image_downloader::ImageDownloaderPtr mojo_image_downloader_;
+
   // NOTE: This must be the last member.
   base::WeakPtrFactory<RenderFrameHostImpl> weak_ptr_factory_;