Replace image_messages.h with Mojo service

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index 8dc4395003b355fffabc072338aeeb9e7e51a4e3..884aaaabb7b03dc64c8b3891fb20c090df9aac32 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -1852,6 +1852,9 @@ void RenderFrameHostImpl::InvalidateMojoConnection() {
 #endif
 
   service_registry_.reset();
+
+  // Disconnect with ImageDownloader Mojo service in RenderFrame.
+  mojo_image_downloader_.reset();
 }
 
 bool RenderFrameHostImpl::IsFocused() {
@@ -1864,6 +1867,15 @@ bool RenderFrameHostImpl::IsFocused() {
           frame_tree_->GetFocusedFrame()->IsDescendantOf(frame_tree_node()));
 }
 
+const image_downloader::ImageDownloaderPtr&
+RenderFrameHostImpl::GetMojoImageDownloader() {
+  if (!mojo_image_downloader_.get()) {
+    GetServiceRegistry()->ConnectToRemoteService(
+        mojo::GetProxy(&mojo_image_downloader_));
+  }
+  return mojo_image_downloader_;
+}
+
 void RenderFrameHostImpl::UpdateCrossProcessIframeAccessibility(
     const std::map<int32, int>& node_to_frame_routing_id_map) {
   for (const auto& iter : node_to_frame_routing_id_map) {