Slop region check for multi-finger scroll

ui/aura/gestures/gesture_recognizer_unittest.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 <stdint.h>
 
 #include <list>
 
 #include "base/command_line.h"
 #include "base/location.h"
@@ skipping 2558 matching lines @@
       delegate->events(), ui::ET_GESTURE_BEGIN, ui::ET_GESTURE_TAP_DOWN);
 
   delegate->Reset();
   ui::TouchEvent press2(ui::ET_TOUCH_PRESSED, gfx::Point(130, 201),
                         kTouchId2, tes.Now());
   DispatchEventUsingWindowDispatcher(&press2);
   EXPECT_2_EVENTS(
       delegate->events(), ui::ET_GESTURE_TAP_CANCEL, ui::ET_GESTURE_BEGIN);
 
   // Little bit of touch move should not affect our state.
+  // Moving within slop region doesn't cause scrolling.
   delegate->Reset();
   ui::TouchEvent move1(ui::ET_TOUCH_MOVED, gfx::Point(102, 202),
                        kTouchId1, tes.Now());
   DispatchEventUsingWindowDispatcher(&move1);
   ui::TouchEvent move2(ui::ET_TOUCH_MOVED, gfx::Point(131, 202),
                        kTouchId2, tes.Now());
   DispatchEventUsingWindowDispatcher(&move2);
-  EXPECT_3_EVENTS(delegate->events(), ui::ET_GESTURE_SCROLL_BEGIN,
-                  ui::ET_GESTURE_SCROLL_UPDATE, ui::ET_GESTURE_SCROLL_UPDATE);

[tdresser, 2016/07/01 14:29:15]

Can we expect some number of events here?

[sahel, 2016/07/05 20:36:34]

Done.

 
   // Make sure there is enough delay before the touch is released so that it is
   // recognized as a tap.
   delegate->Reset();
   ui::TouchEvent release1(ui::ET_TOUCH_RELEASED, gfx::Point(101, 201),
                           kTouchId1, tes.LeapForward(50));
 
   DispatchEventUsingWindowDispatcher(&release1);
   EXPECT_2_EVENTS(
       delegate->events(), ui::ET_GESTURE_TWO_FINGER_TAP, ui::ET_GESTURE_END);
 
   // Lift second finger.
-  // Make sure there is enough delay before the touch is released so that it is
-  // recognized as a tap.
+  // Two fingers have been down at some point during the current touch,
+  // single tap doesn't happen while releasing the second finger.
   delegate->Reset();
   ui::TouchEvent release2(ui::ET_TOUCH_RELEASED, gfx::Point(130, 201),
                           kTouchId2, tes.LeapForward(50));
 
   DispatchEventUsingWindowDispatcher(&release2);
-  EXPECT_2_EVENTS(
-      delegate->events(), ui::ET_GESTURE_SCROLL_END, ui::ET_GESTURE_END);
+  EXPECT_1_EVENT(delegate->events(), ui::ET_GESTURE_END);
 }
 
 TEST_F(GestureRecognizerTest, TwoFingerTapExpired) {
   std::unique_ptr<GestureEventConsumeDelegate> delegate(
       new GestureEventConsumeDelegate());
   const int kWindowWidth = 123;
   const int kWindowHeight = 45;
   const int kTouchId1 = 2;
   const int kTouchId2 = 3;
   gfx::Rect bounds(100, 200, kWindowWidth, kWindowHeight);
@@ skipping 1823 matching lines @@
   EXPECT_FALSE(queued_delegate2->long_press());
 
   queued_delegate->Reset();
   queued_delegate->WaitUntilReceivedGesture(ui::ET_GESTURE_SHOW_PRESS);
   EXPECT_TRUE(queued_delegate->show_press());
   EXPECT_FALSE(queued_delegate->tap_down());
 }
 
 }  // namespace test
 }  // namespace aura