UMA stats to count RenderFrameProxyHosts

content/browser/frame_host/render_frame_host_manager.cc

Index: content/browser/frame_host/render_frame_host_manager.cc
diff --git a/content/browser/frame_host/render_frame_host_manager.cc b/content/browser/frame_host/render_frame_host_manager.cc
index cd1684b769a1b7479a79e30536bf586b6eafeec9..03212114c51a63ca4597387490b5dba014a6e5fe 100644
--- a/content/browser/frame_host/render_frame_host_manager.cc
+++ b/content/browser/frame_host/render_frame_host_manager.cc
@@ -2336,6 +2336,10 @@ RenderFrameProxyHost* RenderFrameHostManager::GetRenderFrameProxyHost(
   return nullptr;
 }
 
+int RenderFrameHostManager::GetProxyCount() {
+  return proxy_hosts_.size();

[Charlie Reis, 2016/02/10 22:37:52]

I suppose this also includes RFPHs that aren't live, and thus aren't affecting
renderer memory stats.  That's an edge case, though, so we should probably
ignore it.

[ncarter (slow), 2016/02/10 23:22:14]

Acknowledged.

+}
+
 std::map<int, RenderFrameProxyHost*>
 RenderFrameHostManager::GetAllProxyHostsForTesting() {
   std::map<int, RenderFrameProxyHost*> result;