Per-host V8 histograms.

content/renderer/render_view_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
@@ skipping 1100 matching lines @@
               &params.browser_initiated_post_data.front()),
           params.browser_initiated_post_data.size()));
       request.setHTTPBody(http_body);
     }
 
     main_frame->loadRequest(request);
   }
 
   // In case LoadRequest failed before DidCreateDataSource was called.
   pending_navigation_params_.reset();
+
+  // Check if all RenderViewImpls are displaying a page from the same host, and
+  // update RenderThreadImpl's view on that. If this is the only RenderViewImpl,
+  // the common host is this view's host. If there are many, check if this one
+  // shares the common host of the other RenderViewImpls. It's ok to not detect
+  // some cases where the RenderViewImpls share a common host.

[Charlie Reis, 2012/08/16 16:22:56]

This isn't safe.  You'll miss renderer-initiated navigations (e.g., link clicks,
frame navigations, etc), and it'll often be wrong due to redirects and
downloads.  It's much safer to watch commits instead.

[marja, 2012/08/21 15:21:15]

Changed this to do the work in RenderViewImpl::didCommitProvisionalLoad. It only
tracks top frame navigations, and ignores subframes. We only take the top frame
host into account when deciding whether to produce a custom diagram since the
subframes are considered to be a part of the page.

+  RenderThreadImpl* render_thread_impl = RenderThreadImpl::current();
+  if (g_view_map.Get().size() == 1)
+    render_thread_impl->SetCommonHost(params.url.host());
+  else if (params.url.host() != render_thread_impl->CommonHost())
+    render_thread_impl->SetCommonHost(std::string());
 }
 
 bool RenderViewImpl::IsBackForwardToStaleEntry(
     const ViewMsg_Navigate_Params& params,
     bool is_reload) {
   // Make sure this isn't a back/forward to an entry we have already cropped
   // or replaced from our history, before the browser knew about it.  If so,
   // a new navigation has committed in the mean time, and we can ignore this.
   bool is_back_forward = !is_reload && !params.state.empty();
 
@@ skipping 4643 matching lines @@
 bool RenderViewImpl::WebWidgetHandlesCompositorScheduling() const {
   return !!RenderThreadImpl::current()->compositor_thread();
 }
 
 void RenderViewImpl::OnJavaBridgeInit() {
   DCHECK(!java_bridge_dispatcher_);
 #if defined(ENABLE_JAVA_BRIDGE)
   java_bridge_dispatcher_ = new JavaBridgeDispatcher(this);
 #endif
 }