Convert ChromeViewHostMsg_UpdatedCacheStats to use mojo.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index a61f179800d488780e4cf85c69ba42f69e70aa89..dd7845082677621eb03736d7d3ab9d2f63df0e97 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -1376,8 +1376,12 @@ void RenderProcessHostImpl::RegisterMojoInterfaces() {
           base::Unretained(
               memory_instrumentation::CoordinatorImpl::GetInstance())));
 
-  GetContentClient()->browser()->ExposeInterfacesToRenderer(registry.get(),
-                                                            this);
+  associated_interfaces_.reset(new AssociatedInterfaceRegistryImpl());
+  GetContentClient()->browser()->ExposeInterfacesToRenderer(
+      registry.get(), associated_interfaces_.get(), this);
+  static_cast<AssociatedInterfaceRegistry*>(associated_interfaces_.get())
+      ->AddInterface(base::Bind(&RenderProcessHostImpl::BindRouteProvider,
+                                base::Unretained(this)));
 
   ServiceManagerConnection* service_manager_connection =
       BrowserContext::GetServiceManagerConnectionFor(browser_context_);
@@ -1389,6 +1393,13 @@ void RenderProcessHostImpl::RegisterMojoInterfaces() {
       std::move(connection_filter));
 }
 
+void RenderProcessHostImpl::BindRouteProvider(
+    mojom::RouteProviderAssociatedRequest request) {
+  if (route_provider_binding_.is_bound())
+    return;
+  route_provider_binding_.Bind(std::move(request));
+}
+
 void RenderProcessHostImpl::GetRoute(
     int32_t routing_id,
     mojom::AssociatedInterfaceProviderAssociatedRequest request) {
@@ -2138,12 +2149,9 @@ bool RenderProcessHostImpl::OnMessageReceived(const IPC::Message& msg) {
 void RenderProcessHostImpl::OnAssociatedInterfaceRequest(
     const std::string& interface_name,
     mojo::ScopedInterfaceEndpointHandle handle) {
-  if (interface_name == mojom::RouteProvider::Name_) {
-    if (route_provider_binding_.is_bound())
-      return;
-    mojom::RouteProviderAssociatedRequest request;
-    request.Bind(std::move(handle));
-    route_provider_binding_.Bind(std::move(request));
+  if ((associated_interfaces_) &&

[Ken Rockot(use gerrit already), 2017/04/28 19:20:10]

nit: please remove the redundant parenthesis from both of these expressions.
there is no potential ambiguity to be guarded against and so they add no value

[nigeltao1, 2017/04/29 07:07:57]

Done.

+      (associated_interfaces_->CanBindRequest(interface_name))) {
+    associated_interfaces_->BindRequest(interface_name, std::move(handle));
   } else {
     LOG(ERROR) << "Request for unknown Channel-associated interface: "
                << interface_name;
@@ -2803,6 +2811,7 @@ void RenderProcessHostImpl::ProcessDied(bool already_dead,
   is_dead_ = true;
   if (route_provider_binding_.is_bound())
     route_provider_binding_.Close();
+  associated_interfaces_.reset(NULL);

[Ken Rockot(use gerrit already), 2017/04/28 19:20:10]

nit: please use nullptr instead of NULL in new code. but here you should in fact
just reset().

It's totally fine if you really want to reset associated_interfaces_ here, but
that has absolutely nothing to do with closing existing bound interfaces. It's
just a map of callbacks that are used to bind incoming requests. If you want to
close bound interfaces too, you have to do that explicitly (e.g. look at how
route_provider_binding_ is closed above).

The use of StrongAssociatedBinding for your interface makes it impossible for
you to force-close the pipe at your own discretion. Because it's a
Channel-associated interface, however, it is impossible for it to outlive the
IPC::Channel anyway, so I don't think there's actually any risk here.

[nigeltao1, 2017/04/29 07:07:57]

Done.

   ResetChannelProxy();
 
   UpdateProcessPriority();