Add a RWH_TabSwitchPaintDuration histogram.

The RWH_TabSwitchPaintDuration histogram calculates
the amount of time it took after a particular view was
selected for it to be fully painted.

I modified the tab switching test to use the new tab
switch paint duration histogram in place of the whiteout
duration histogram.  As a measure, whiteout duration
would not carry a value if we kept the backing store
around for a tab, and we would end up with a result of
zero instead of a useful result.  Local results with the
new measure are consistent with the number of operations
we perform on the tabs.

The tab switching test now fails if it cannot locate
the correct histogram.  In that case, it will output
the contents of the log file for remote debugging.

BUG=4104
TEST=count of tab switch paint duration histogram
results in tab switching test equals number of tabs
used in test

First committed as: http://src.chromium.org/viewvc/chrome?view=rev&revision=31632
Reverted in: 31645

Review URL: http://codereview.chromium.org/378038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@31679 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 3 insertions, 0 deletions

diff --git a/chrome/browser/renderer_host/render_widget_host_view_mac.h b/chrome/browser/renderer_host/render_widget_host_view_mac.h
index 9d6ffbb..67c8abf 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_mac.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_mac.h
@@ -140,6 +140,9 @@ class RenderWidgetHostViewMac : public RenderWidgetHostView {
   // value returns true for is_null() if we are not recording whiteout times.
   base::TimeTicks whiteout_start_time_;
 
+  // The time it took after this view was selected for it to be fully painted.
+  base::TimeTicks tab_switch_paint_time_;
+
   // Variables used by our implementaion of the NSTextInput protocol.
   // An input method of Mac calls the methods of this protocol not only to
   // notify an application of its status, but also to retrieve the status of