First crack at implementing the touch explaration mode.

ui/events/gestures/gesture_sequence.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 "ui/events/gestures/gesture_sequence.h"
 
 #include <stdlib.h>
 #include <cmath>
 #include <limits>
 
@@ skipping 494 matching lines @@
 }
 
 GestureSequence::Gestures* GestureSequence::ProcessTouchEventForGesture(
     const TouchEvent& event,
     EventResult result) {
   StopTimersIfRequired(event);
   last_touch_location_ = event.location();
   if (result & ER_CONSUMED)
     return NULL;
 
+  LOG(ERROR) << "GS::ProcessTouchEventForGesture, type=" << event.type();
   // Set a limit on the number of simultaneous touches in a gesture.
   if (event.touch_id() >= kMaxGesturePoints)
     return NULL;
 
   if (event.type() == ui::ET_TOUCH_PRESSED) {
     if (point_count_ == kMaxGesturePoints)
       return NULL;
     GesturePoint* new_point = &points_[event.touch_id()];
     // We shouldn't be able to get two PRESSED events from the same
     // finger without either a RELEASE or CANCEL in between. But let's not crash
@@ skipping 953 matching lines @@
 }
 
 void GestureSequence::StartRailFreeScroll(const GesturePoint& point,
                                           Gestures* gestures) {
   AppendScrollGestureBegin(point, point.first_touch_position(), gestures);
   scroll_type_ = ST_FREE;
   set_state(GS_SCROLL);
 }
 
 }  // namespace ui