input: Make the OverscrollController less intrusive, and some code cleanup.

content/browser/renderer_host/overscroll_controller.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/browser/renderer_host/overscroll_controller.h"
 
 #include "content/browser/renderer_host/overscroll_controller_delegate.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/public/browser/overscroll_configuration.h"
 #include "content/public/browser/render_widget_host_view.h"
@@ skipping 46 matching lines @@
   }
 
   if (DispatchEventCompletesAction(event)) {
     CompleteAction();
 
     // If the overscroll was caused by touch-scrolling, then the gesture event
     // that completes the action needs to be sent to the renderer, because the
     // touch-scrolls maintain state in the renderer side (in the compositor, for
     // example), and the event that completes this action needs to be sent to
     // the renderer so that those states can be updated/reset appropriately.
-    // Send the event through the host when appropriate.
-    if (ShouldForwardToHost(event)) {
+    if (WebKit::WebInputEvent::isGestureEventType(event.type)) {
       const WebKit::WebGestureEvent& gevent =
           static_cast<const WebKit::WebGestureEvent&>(event);
       return render_widget_host_->ShouldForwardGestureEvent(
           GestureEventWithLatencyInfo(gevent, latency_info));
     }
 
     return false;
   }
 
   if (overscroll_mode_ != OVERSCROLL_NONE && DispatchEventResetsState(event)) {
     SetOverscrollMode(OVERSCROLL_NONE);
     // The overscroll gesture status is being reset. If the event is a
     // gesture event (from either touchscreen or trackpad), then make sure the
-    // host gets the event first (if it didn't already process it).
-    if (ShouldForwardToHost(event)) {
+    // host gets the event first.
+    if (WebKit::WebInputEvent::isGestureEventType(event.type)) {
       const WebKit::WebGestureEvent& gevent =
           static_cast<const WebKit::WebGestureEvent&>(event);
       return render_widget_host_->ShouldForwardGestureEvent(
           GestureEventWithLatencyInfo(gevent, latency_info));
     }
 
     // Let the event be dispatched to the renderer.

[aelias_OOO_until_Jul13, 2013/09/03 02:24:10]

I don't think the OverscrollController should be making any decisions about
event dispatch.  Can't overscroll be implemented entirely using passive
listening?  I would really like to see this code moved out of here.

     return true;
   }
 
   if (overscroll_mode_ != OVERSCROLL_NONE) {
     // Consume the event and update overscroll state when in the middle of the
     // overscroll gesture.
     ProcessEventForOverscroll(event);
 
     if (event.type == WebKit::WebInputEvent::TouchEnd ||
         event.type == WebKit::WebInputEvent::TouchCancel ||
@@ skipping 259 matching lines @@
   OverscrollMode old_mode = overscroll_mode_;
   overscroll_mode_ = mode;
   if (overscroll_mode_ == OVERSCROLL_NONE)
     overscroll_delta_x_ = overscroll_delta_y_ = 0.f;
   else
     scroll_state_ = STATE_OVERSCROLLING;
   if (delegate_)
     delegate_->OnOverscrollModeChange(old_mode, overscroll_mode_);
 }
 
-bool OverscrollController::ShouldForwardToHost(
-    const WebKit::WebInputEvent& event) const {
-  if (!WebKit::WebInputEvent::isGestureEventType(event.type))
-    return false;
-
-  // If the RenderWidgetHost already processed this event, then the event must
-  // not be sent again.
-  return !render_widget_host_->HasQueuedGestureEvents();
-}
-
 }  // namespace content