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

content/browser/webui/web_ui_mojo_browsertest.cc

Index: content/browser/webui/web_ui_mojo_browsertest.cc
diff --git a/content/browser/webui/web_ui_mojo_browsertest.cc b/content/browser/webui/web_ui_mojo_browsertest.cc
index 5007a8da6a0872686d63cddb5b2875cf2f694074..8abb3b8d0c32fa12228ca205366e8ddd6e9b682e 100644
--- a/content/browser/webui/web_ui_mojo_browsertest.cc
+++ b/content/browser/webui/web_ui_mojo_browsertest.cc
@@ -12,12 +12,15 @@
 #include "base/strings/string_util.h"
 #include "content/browser/webui/web_ui_controller_factory_registry.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui_controller.h"
 #include "content/public/browser/web_ui_data_source.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/common/content_switches.h"
+#include "content/public/common/service_registry.h"
 #include "content/public/common/url_utils.h"
 #include "content/public/test/content_browser_test.h"
 #include "content/public/test/content_browser_test_utils.h"
@@ -125,13 +128,19 @@ class PingTestWebUIController : public TestWebUIController {
    PingTestWebUIController(WebUI* web_ui, base::RunLoop* run_loop)
        : TestWebUIController(web_ui, run_loop) {
    }
+   virtual ~PingTestWebUIController() {}
 
   // WebUIController overrides:
   virtual void RenderViewCreated(RenderViewHost* render_view_host) OVERRIDE {
-    mojo::MessagePipe pipe;
-    browser_target_.reset(
-        new PingBrowserTargetImpl(pipe.handle0.Pass(), run_loop_));
-    render_view_host->SetWebUIHandle(pipe.handle1.Pass());
+    render_view_host->GetProcess()->ActivateMojo();
+    render_view_host->GetMainFrame()->GetServiceRegistry()->AddService(
+        "webui_controller",
+        base::Bind(&PingTestWebUIController::CreateHandler,
+                   base::Unretained(this)));
+  }
+
+  void CreateHandler(mojo::ScopedMessagePipeHandle handle) {
+    browser_target_.reset(new PingBrowserTargetImpl(handle.Pass(), run_loop_));
   }
 
  private: