Support exposing Mojo services between render frames, render threads, and their respective hosts.

content/renderer/web_ui_mojo.cc

 // 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.
 
 #include "content/renderer/web_ui_mojo.h"
 
 #include "content/common/view_messages.h"
+#include "content/public/common/service_registry.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_view.h"
 #include "content/renderer/web_ui_mojo_context_state.h"
 #include "gin/per_context_data.h"
 #include "third_party/WebKit/public/web/WebKit.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebView.h"
 #include "v8/include/v8.h"
 
 namespace content {
@@ skipping 59 matching lines @@
 
 void WebUIMojo::DestroyContextState(v8::Handle<v8::Context> context) {
   gin::PerContextData* context_data = gin::PerContextData::From(context);
   if (!context_data)
     return;
   context_data->RemoveUserData(kWebUIMojoContextStateKey);
 }
 
 void WebUIMojo::OnDidFinishDocumentLoad() {
   did_finish_document_load_ = true;
-  if (pending_handle_.is_valid())
-    SetHandleOnContextState(pending_handle_.Pass());
+  mojo::MessagePipe pipe;
+  SetHandleOnContextState(pipe.handle0.Pass());
+  RenderFrame::FromWebFrame(render_view()->GetWebView()->mainFrame())
+      ->GetServiceRegistry()

[darin (slow to review), 2014/06/21 04:33:35]

nit: "Wrap after binary operators, not before." from
http://dev.chromium.org/developers/coding-style

RenderFrame::FromWebFrame(...)->
    GetServiceRegistry()->
        GetRemoteInterface(...);

[Sam McNally, 2014/06/24 04:00:29]

Done.

+      ->GetRemoteInterface("webui_controller", pipe.handle1.Pass());
 }
 
 void WebUIMojo::SetHandleOnContextState(mojo::ScopedMessagePipeHandle handle) {
   DCHECK(did_finish_document_load_);
   v8::HandleScope handle_scope(blink::mainThreadIsolate());
   WebUIMojoContextState* state = GetContextState();
   if (state)
     state->SetHandle(handle.Pass());
 }
 
@@ skipping 25 matching lines @@
   WebUIMojoContextState* state = GetContextState();
   if (state && !state->module_added())
     return;
 
   v8::HandleScope handle_scope(blink::mainThreadIsolate());
   DestroyContextState(frame->mainWorldScriptContext());
   CreateContextState();
 }
 
 }  // namespace content