Fixed NOTREACHED() bug in touch_exploration_controller.

Now when double tapping with no last touch exploration location, the tap timer is no longer fired, which was previously entering no fingers down state when a finger was actually down.

TEST=TouchExplorationTest.DoubleTapNoTouchExplore
BUG=397296

Review URL: https://codereview.chromium.org/419923002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285693 0039d316-1c4b-4281-b951-d872f2087c98

ui/chromeos/touch_exploration_controller.cc

@@ -243,15 +243,12 @@ TouchExplorationController::InSingleTapOrTouchExploreReleased(
     state_ = WAIT_FOR_RELEASE;
     return ui::EVENT_REWRITE_DISCARD;
   }
-  // If there is no touch exploration yet, discard.
-  if (!last_touch_exploration_ || type == ui::ET_TOUCH_RELEASED) {
-    if (current_touch_ids_.size() == 0) {
-      ResetToNoFingersDown();
-    }
-    return ui::EVENT_REWRITE_DISCARD;
-  }
-
   if (type == ui::ET_TOUCH_PRESSED) {
+    // If there is no touch exploration yet, we can't send a click, so discard.
+    if (!last_touch_exploration_) {
+      tap_timer_.Stop();
+      return ui::EVENT_REWRITE_DISCARD;
+    }
     // This is the second tap in a double-tap (or double tap-hold).
     // Rewrite at location of last touch exploration.
     rewritten_event->reset(

ui/chromeos/touch_exploration_controller_unittest.cc

@@ -752,7 +752,13 @@ TEST_F(TouchExplorationTest, DoubleTapNoTouchExplore) {
   generator_->PressTouch();
   generator_->ReleaseTouch();
   generator_->PressTouch();
+  // Since the state stays in single_tap_released, we need to make sure the
+  // tap timer doesn't fire and set the state to no fingers down (since there
+  // is still a finger down).
+  AdvanceSimulatedTimePastPotentialTapDelay();
+  EXPECT_FALSE(IsInNoFingersDownState());
   generator_->ReleaseTouch();
+  EXPECT_TRUE(IsInNoFingersDownState());
 
   std::vector<ui::LocatedEvent*> captured_events = GetCapturedLocatedEvents();
   ASSERT_EQ(0U, captured_events.size());