Android mouse events shouldn't appear as TouchEvents

ui/events/gesture_detection/gesture_detector.cc

 // Copyright 2014 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.
 
 // MSVC++ requires this to be set before any other includes to get M_PI.
 #define _USE_MATH_DEFINES
 
 #include "ui/events/gesture_detection/gesture_detector.h"
 
 #include <stddef.h>
@@ skipping 160 matching lines @@
     sum_y += ev.GetY(i);
   }
   const int div = pointer_up ? count - 1 : count;
   const float focus_x = sum_x / div;
   const float focus_y = sum_y / div;
 
   bool handled = false;
 
   switch (action) {
     case MotionEvent::ACTION_NONE:
+    case MotionEvent::ACTION_HOVER_ENTER:
+    case MotionEvent::ACTION_HOVER_EXIT:
+    case MotionEvent::ACTION_HOVER_MOVE:
+    case MotionEvent::ACTION_BUTTON_PRESS:
+    case MotionEvent::ACTION_BUTTON_RELEASE:
       NOTREACHED();
       return handled;
 
     case MotionEvent::ACTION_POINTER_DOWN: {
       down_focus_x_ = last_focus_x_ = focus_x;
       down_focus_y_ = last_focus_y_ = focus_y;
       // Cancel long press and taps.
       CancelTaps();
       maximum_pointer_count_ = std::max(maximum_pointer_count_,
                                         static_cast<int>(ev.GetPointerCount()));
@@ skipping 389 matching lines @@
   for (size_t i = 0; i < secondary_pointer_down_event.GetPointerCount(); i++) {
     if (secondary_pointer_down_event.GetPointerId(i) == pointer_id)
       return &secondary_pointer_down_event;
   }
 
   NOTREACHED();
   return nullptr;
 }
 
 }  // namespace ui