Adds RenderWidgetHostWillPaint. I need this for something else I'm

working on.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/3152026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@56578 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 8 insertions, 3 deletions

diff --git a/chrome/browser/dom_ui/new_tab_ui.cc b/chrome/browser/dom_ui/new_tab_ui.cc
index 6b97778..7fe8ee8 100644
--- a/chrome/browser/dom_ui/new_tab_ui.cc
+++ b/chrome/browser/dom_ui/new_tab_ui.cc
@@ -74,6 +74,8 @@ class PaintTimer : public RenderWidgetHost::PaintObserver {
   }
 
   // A callback that is invoked whenever our RenderWidgetHost paints.
+  virtual void RenderWidgetHostWillPaint(RenderWidgetHost* rhw) {}
+
   virtual void RenderWidgetHostDidPaint(RenderWidgetHost* rwh) {
     last_paint_ = base::TimeTicks::Now();
   }
diff --git a/chrome/browser/renderer_host/render_widget_host.cc b/chrome/browser/renderer_host/render_widget_host.cc
index 774b682..b9e1b8c 100644
--- a/chrome/browser/renderer_host/render_widget_host.cc
+++ b/chrome/browser/renderer_host/render_widget_host.cc
@@ -721,6 +721,9 @@ void RenderWidgetHost::OnMsgUpdateRect(
     const ViewHostMsg_UpdateRect_Params& params) {
   TimeTicks paint_start = TimeTicks::Now();
 
+  if (paint_observer_.get())
+    paint_observer_->RenderWidgetHostWillPaint(this);
+
   // Update our knowledge of the RenderWidget's size.
   current_size_ = params.view_size;
 
diff --git a/chrome/browser/renderer_host/render_widget_host.h b/chrome/browser/renderer_host/render_widget_host.h
index 355aefa..eac130e 100644
--- a/chrome/browser/renderer_host/render_widget_host.h
+++ b/chrome/browser/renderer_host/render_widget_host.h
@@ -124,11 +124,11 @@ struct ViewHostMsg_UpdateRect_Params;
 class RenderWidgetHost : public IPC::Channel::Listener,
                          public IPC::Channel::Sender {
  public:
-  // An interface that gets called whenever a paint occurs.
-  // Used in performance tests.
+  // An interface that gets called before and after a paint.
   class PaintObserver {
    public:
     virtual ~PaintObserver() {}
+    virtual void RenderWidgetHostWillPaint(RenderWidgetHost* rhw) = 0;
     virtual void RenderWidgetHostDidPaint(RenderWidgetHost* rwh) = 0;
   };
 
diff --git a/chrome/browser/renderer_host/render_widget_host_painting_observer.h b/chrome/browser/renderer_host/render_widget_host_painting_observer.h
index 8b3da5e..3c6c867 100644
--- a/chrome/browser/renderer_host/render_widget_host_painting_observer.h
+++ b/chrome/browser/renderer_host/render_widget_host_painting_observer.h
@@ -8,7 +8,6 @@
 
 class BackingStore;
 class RenderWidgetHost;
-class SkBitmap;
 
 namespace gfx {
 class Size;
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index f2c2ec7..2adbedb 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -2258,6 +2258,7 @@
         'browser/renderer_host/render_widget_helper.h',
         'browser/renderer_host/render_widget_host.cc',
         'browser/renderer_host/render_widget_host.h',
+        'browser/renderer_host/render_widget_host_painting_observer.h',
         'browser/renderer_host/render_widget_host_view.h',
         'browser/renderer_host/render_widget_host_view_gtk.cc',
         'browser/renderer_host/render_widget_host_view_gtk.h',