media: Add ProvisionFetcher mojo interface and implementation.

content/browser/frame_host/frame_mojo_shell.cc

Index: content/browser/frame_host/frame_mojo_shell.cc
diff --git a/content/browser/frame_host/frame_mojo_shell.cc b/content/browser/frame_host/frame_mojo_shell.cc
index 3176fc01b675e821026333aea54826fdde4ed555..9e4dace9a93744f4da4e5c56c2aa41a9077fbd4f 100644
--- a/content/browser/frame_host/frame_mojo_shell.cc
+++ b/content/browser/frame_host/frame_mojo_shell.cc
@@ -16,6 +16,10 @@
 #include "content/public/common/content_client.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 
+#if defined(OS_ANDROID) && defined(ENABLE_MOJO_MEDIA)
+#include "content/browser/media/android/provision_fetcher_impl.h"
+#endif
+
 namespace content {
 
 namespace {
@@ -41,6 +45,14 @@ class ServiceRegistryWrapper : public mojo::ServiceProvider {
   DISALLOW_COPY_AND_ASSIGN(ServiceRegistryWrapper);
 };
 
+void RegisterFrameMojoShellServices(ServiceRegistry* registry,
+                                    RenderFrameHost* render_frame_host) {
+#if defined(OS_ANDROID) && defined(ENABLE_MOJO_MEDIA)
+  registry->AddService(
+      base::Bind(&ProvisionFetcherImpl::Create, render_frame_host));
+#endif
+}
+
 }  // namespace
 
 FrameMojoShell::FrameMojoShell(RenderFrameHost* frame_host)
@@ -84,6 +96,7 @@ void FrameMojoShell::QuitApplication() {
 mojo::ServiceProvider* FrameMojoShell::GetServiceProvider() {
   if (!service_provider_) {
     scoped_ptr<ServiceRegistryImpl> registry(new ServiceRegistryImpl());
+    RegisterFrameMojoShellServices(registry.get(), frame_host_);
     GetContentClient()->browser()->RegisterFrameMojoShellServices(
         registry.get(), frame_host_);

[xhwang, 2015/11/20 22:28:34]

rockot:

These services will always be provided by the browser no matter what app we are
connecting to. But really some services are only provided to certain app. For
example, the ProvisionFetcher service is only needed by the MojoMediaApplication
on Android.

I wonder whether we should has some means to only provide some service when
certain app is being connected.

[Ken Rockot(use gerrit already), 2015/11/24 17:35:58]

Side note: After getting thoroughly confused by this I think I'm realizing we
need to reconsider how things are done here so it's more clear.

In general though I think it's OK to leave things as they are for now. Maybe we
should just initialize a new ServiceProvider for every outgoing application
connection. It wouldn't be much additional overhead.

No need to worry about it for this CL though IMHO.

[xhwang, 2015/11/24 19:43:21]

Ack. Added a TODO to remind us of this issue/discussion.

     service_provider_.reset(new ServiceRegistryWrapper(std::move(registry)));