Per-host V8 histograms.

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index c8669bbdec789fc5afa25e4797b5ef653f44fa5f..73851123f6e30e9ec44fc99f935e8dd80cff54ff 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -3209,6 +3209,11 @@ void RenderViewImpl::didCommitProvisionalLoad(WebFrame* frame,
 
   // Check whether we have new encoding name.
   UpdateEncoding(frame, frame->view()->pageEncoding().utf8());
+
+  if (!frame->parent()) {  // Only for top frames.
+    RenderThreadImpl::current()->RenderViewNavigatedToHost(GURL(
+        frame->document().url()).host(), g_view_map.Get().size());

[Charlie Reis, 2012/08/22 23:09:59]

We should probably use GetLoadingURL, or move this to UpdateURL and use
params.url.

[marja, 2012/08/23 14:15:00]

Done.

+  }
 }
 
 void RenderViewImpl::didClearWindowObject(WebFrame* frame) {