Make RootView::DispatchGestureEvent() non-virtual

chrome/browser/ui/views/frame/browser_root_view.cc

Index: chrome/browser/ui/views/frame/browser_root_view.cc
diff --git a/chrome/browser/ui/views/frame/browser_root_view.cc b/chrome/browser/ui/views/frame/browser_root_view.cc
index 6ac54d94e37a60e78e28cc2e515e358b00624ca1..f388211178d033fd752bfa0d6350a9a257ffcaf4 100644
--- a/chrome/browser/ui/views/frame/browser_root_view.cc
+++ b/chrome/browser/ui/views/frame/browser_root_view.cc
@@ -151,14 +151,17 @@ bool BrowserRootView::OnMouseWheel(const ui::MouseWheelEvent& event) {
   return RootView::OnMouseWheel(event);
 }
 
-void BrowserRootView::DispatchGestureEvent(ui::GestureEvent* event) {
-  if (event->type() == ui::ET_GESTURE_TAP &&
-      event->location().y() <= 0 &&
-      event->location().x() <= browser_view_->GetBounds().width()) {
-    TouchUMA::RecordGestureAction(TouchUMA::GESTURE_ROOTVIEWTOP_TAP);
+ui::EventDispatchDetails BrowserRootView::OnEventFromSource(ui::Event* event) {
+  if (event->IsGestureEvent()) {

[sky, 2014/07/15 20:53:11]

I'm not a fan of the static_casts all through out the code. They are easy to get
wrong. WDYT of isolating the static_cast in ui::Event:

ui::GestureEvent* AsGestureEvent() {
  return IsGestureEvent() ? static_cast<GestureEvent*>(this) : NULL;
}
? This code then becomes:

ui::GestureEvent* gesture_event = event->AsGestureEvent();
if (gesture_event) {....

[tdanderson, 2014/07/15 21:31:24]

Yes, I agree that isolating the static_casts in this manner would be a lot
nicer. But how about instead making IsGestureEvent() a precondition:

ui::GestureEvent* AsGestureEvent() {
  CHECK(IsGestureEvent());
  return static_cast<GestureEvent*>(this);
}

?

+    ui::GestureEvent* gesture_event = static_cast<ui::GestureEvent*>(event);
+    if (gesture_event->type() == ui::ET_GESTURE_TAP &&
+        gesture_event->location().y() <= 0 &&
+        gesture_event->location().x() <= browser_view_->GetBounds().width()) {
+      TouchUMA::RecordGestureAction(TouchUMA::GESTURE_ROOTVIEWTOP_TAP);
+    }
   }
 
-  RootView::DispatchGestureEvent(event);
+  return RootView::OnEventFromSource(event);
 }
 
 bool BrowserRootView::ShouldForwardToTabStrip(