Add UMA counter for hung renderers on cross-site navigation.

content/browser/renderer_host/resource_dispatcher_host_impl.cc

Index: content/browser/renderer_host/resource_dispatcher_host_impl.cc
diff --git a/content/browser/renderer_host/resource_dispatcher_host_impl.cc b/content/browser/renderer_host/resource_dispatcher_host_impl.cc
index dd6bf7de3b50124e89ef71be0938217fb2cd4334..18e3a10a5b771b4b48b4bec2871c6ea93c223e86 100644
--- a/content/browser/renderer_host/resource_dispatcher_host_impl.cc
+++ b/content/browser/renderer_host/resource_dispatcher_host_impl.cc
@@ -261,11 +261,13 @@ net::RequestPriority DetermineRequestPriority(ResourceType::Type type) {
   }
 }
 
-void OnSwapOutACKHelper(int render_process_id, int render_view_id) {
+void OnSwapOutACKHelper(int render_process_id,
+                        int render_view_id,
+                        bool timed_out) {
   RenderViewHostImpl* rvh = RenderViewHostImpl::FromID(render_process_id,
                                                        render_view_id);
   if (rvh)
-    rvh->OnSwapOutACK();
+    rvh->OnSwapOutACK(timed_out);
 }
 
 net::Error CallbackAndReturn(
@@ -1184,8 +1186,20 @@ ResourceRequestInfoImpl* ResourceDispatcherHostImpl::CreateRequestInfo(
       context);
 }
 
+
 void ResourceDispatcherHostImpl::OnSwapOutACK(
+  const ViewMsg_SwapOut_Params& params) {
+  HandleSwapOutACK(params, false);
+}
+
+void ResourceDispatcherHostImpl::OnSimulateSwapOutACK(
     const ViewMsg_SwapOut_Params& params) {
+  // Call the real implementation with true, which means that we timed out.
+  HandleSwapOutACK(params, true);
+}
+
+void ResourceDispatcherHostImpl::HandleSwapOutACK(
+    const ViewMsg_SwapOut_Params& params, bool timed_out) {
   // Closes for cross-site transitions are handled such that the cross-site
   // transition continues.
   ResourceLoader* loader = GetLoader(params.new_render_process_host_id,
@@ -1203,7 +1217,8 @@ void ResourceDispatcherHostImpl::OnSwapOutACK(
       FROM_HERE,
       base::Bind(&OnSwapOutACKHelper,
                  params.closing_process_id,
-                 params.closing_route_id));
+                 params.closing_route_id,
+                 timed_out));
 }
 
 void ResourceDispatcherHostImpl::OnDidLoadResourceFromMemoryCache(