Centered flood fill style ink drop ripples on mouse/touch points.

ui/events/event_utils.h

 // 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.
 
 #ifndef UI_EVENTS_EVENT_UTILS_H_
 #define UI_EVENTS_EVENT_UTILS_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 161 matching lines @@
 #if defined(USE_X11)
 // Update the native X11 event to correspond to the new flags.
 EVENTS_EXPORT void UpdateX11EventForFlags(Event* event);
 // Update the native X11 event to correspond to the new button flags.
 EVENTS_EXPORT void UpdateX11EventForChangedButtonFlags(MouseEvent* event);
 #endif
 
 // Registers a custom event type.
 EVENTS_EXPORT int RegisterCustomEventType();
 
+// Convenience function that casts |event| to a LocatedEvent if it is one,
+// otherwise returns null.
+EVENTS_EXPORT const ui::LocatedEvent* ToLocatedEventOrNull(

[sky, 2016/06/16 16:50:02]

+sadrul for his thoughts. I prefer a static on LocatedEvent, and I would go for
a more verbose name to reinforce it checks the type e.g.
LocatedEvent::AsLocatedEventIfLocatedEvent().

[bruthig, 2016/06/16 19:50:02]

Moved to LocatedEvent::AsLocatedEventIfLocatedEvent(), will wait for sadrul@'s
input though.

[sadrul, 2016/06/17 16:03:22]

We could have LocatedEvent::From(ui::Event*); which could return null (we have
some code in other parts that use similar mechanism, e.g.
RenderViewHost::From(RenderWidgetHost*)). We could be a bit more verbose though,
e.g. MaybeFrom(ui::Event*), or FromIfValid(ui::Event*).

+    const ui::Event* event);
+
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_UTILS_H_