Add a RWH_TabSwitchPaintDuration histogram.

chrome/browser/renderer_host/render_widget_host_view_win.cc

 // Copyright (c) 2009 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 "chrome/browser/renderer_host/render_widget_host_view_win.h"
 
 #include "app/gfx/canvas.h"
 #include "app/gfx/gdi_util.h"
 #include "app/l10n_util.h"
 #include "app/l10n_util_win.h"
@@ skipping 237 matching lines @@
 }
 
 RenderWidgetHost* RenderWidgetHostViewWin::GetRenderWidgetHost() const {
   return render_widget_host_;
 }
 
 void RenderWidgetHostViewWin::DidBecomeSelected() {
   if (!is_hidden_)
     return;
 
+  if (tab_switch_paint_time_.is_null())
+    tab_switch_paint_time_ = TimeTicks::Now();
   is_hidden_ = false;
   EnsureTooltip();
   render_widget_host_->WasRestored();
 }
 
 void RenderWidgetHostViewWin::WasHidden() {
   if (is_hidden_)
     return;
 
   // If we receive any more paint messages while we are hidden, we want to
@@ skipping 518 matching lines @@
       DrawBackground(r, &paint_dc);
     }
     if (!whiteout_start_time_.is_null()) {
       TimeDelta whiteout_duration = TimeTicks::Now() - whiteout_start_time_;
       UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration", whiteout_duration);
 
       // Reset the start time to 0 so that we start recording again the next
       // time the backing store is NULL...
       whiteout_start_time_ = TimeTicks();
     }
+    if (!tab_switch_paint_time_.is_null()) {
+      TimeDelta tab_switch_paint_duration = TimeTicks::Now() -
+          tab_switch_paint_time_;
+      UMA_HISTOGRAM_TIMES("MPArch.RWH_TabSwitchPaintDuration",
+          tab_switch_paint_duration);
+      // Reset tab_switch_paint_time_ to 0 so future tab selections are
+      // recorded.
+      tab_switch_paint_time_ = TimeTicks();
+    }
   } else {
     DrawBackground(paint_dc.m_ps.rcPaint, &paint_dc);
     if (whiteout_start_time_.is_null())
       whiteout_start_time_ = TimeTicks::Now();
   }
 }
 
 void RenderWidgetHostViewWin::DrawBackground(const RECT& dirty_rect,
                                              CPaintDC* dc) {
   if (!background_.empty()) {
@@ skipping 596 matching lines @@
     SetFocus();
   }
 }
 
 void RenderWidgetHostViewWin::ShutdownHost() {
   shutdown_factory_.RevokeAll();
   if (render_widget_host_)
     render_widget_host_->Shutdown();
   // Do not touch any members at this point, |this| has been deleted.
 }