Revert of Touch emulator: overwrite timestamps from mouse event with current...

Revert of Touch emulator: overwrite timestamps from mouse event with current time. (https://codereview.chromium.org/250923005/)

Reason for revert:
Somewhat speculative; looks like this caused TouchEmulatorTest failures on valgrind:

http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20Tests%20%28tsan%29%283%29/builds/11052

TouchEmulatorTest.Pinch:
../../content/browser/renderer_host/input/touch_emulator_unittest.cc:254: Failure
Value of: ExpectedEvents()
Actual: "TouchEnd GestureFlingStart"
Expected: "TouchEnd GestureScrollEnd"

etc

Original issue's description:
> Touch emulator: overwrite timestamps from mouse event with current time.
> 
> On some platfroms, mouse events come with a bad timestamp, which leads to
> awkward time-dependent gestures. For example, fling animation may be almost
> instant.
> Using base::TimeTicks::Now() is good enough for emulation purposes, because
> emulator spawns new events itself.
> 
> BUG=367156
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266548

TBR=jdduke@chromium.org,dgozman@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=367156

Review URL: https://codereview.chromium.org/252963002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266610 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/input/touch_emulator.cc

@@ -316,7 +316,7 @@ void TouchEmulator::PinchEnd(const WebGestureEvent& event) {
   client_->ForwardGestureEvent(pinch_event_);
 }
 
-void TouchEmulator::FillPinchEvent(const WebGestureEvent& event) {
+void TouchEmulator::FillPinchEvent(const WebInputEvent& event) {
   pinch_event_.timeStampSeconds = event.timeStampSeconds;
   pinch_event_.modifiers = event.modifiers;
   pinch_event_.sourceDevice = blink::WebGestureEvent::Touchscreen;
@@ -361,16 +361,6 @@ bool TouchEmulator::FillTouchEventAndPoint(const WebMouseEvent& mouse_event) {
   WebTouchEventTraits::ResetTypeAndTouchStates(
       eventType, mouse_event.timeStampSeconds, &touch_event_);
 
-  // On some platforms mouse event's timestamp does not necessarily relate to
-  // the system time at all, so use base::TimeTicks::HighResNow() if possible,
-  // or base::TimeTicks::Now() otherwise.
-  base::TimeTicks now;
-  if (base::TimeTicks::IsHighResNowFastAndReliable())
-    now = base::TimeTicks::HighResNow();
-  else
-    now = base::TimeTicks::Now();
-  touch_event_.timeStampSeconds = (now - base::TimeTicks()).InSecondsF();
-
   WebTouchPoint& point = touch_event_.touches[0];
   point.id = 0;
   point.radiusX = point.radiusY = 1.f;

content/browser/renderer_host/input/touch_emulator.h

@@ -48,7 +48,7 @@ class CONTENT_EXPORT TouchEmulator : public ui::GestureProviderClient {
   bool InPinchGestureMode() const;
 
   bool FillTouchEventAndPoint(const blink::WebMouseEvent& mouse_event);
-  void FillPinchEvent(const blink::WebGestureEvent& event);
+  void FillPinchEvent(const blink::WebInputEvent& event);
 
   // The following methods generate and pass gesture events to the renderer.
   void PinchBegin(const blink::WebGestureEvent& event);

content/browser/renderer_host/input/touch_emulator_unittest.cc

@@ -202,7 +202,7 @@ TEST_F(TouchEmulatorTest, Touch) {
   MouseUp(200, 200);
   EXPECT_EQ(
       "TouchMove GestureTapCancel GestureScrollBegin GestureScrollUpdate"
-      " TouchEnd GestureFlingStart",
+      " TouchEnd GestureScrollEnd",
       ExpectedEvents());
 }
 
@@ -214,13 +214,13 @@ TEST_F(TouchEmulatorTest, MultipleTouches) {
   MouseUp(200, 200);
   EXPECT_EQ(
       "TouchMove GestureTapCancel GestureScrollBegin GestureScrollUpdate"
-      " TouchEnd GestureFlingStart",
+      " TouchEnd GestureScrollEnd",
       ExpectedEvents());
   MouseMove(300, 200);
   MouseMove(200, 200);
   EXPECT_EQ("", ExpectedEvents());
   MouseDown(300, 200);
-  EXPECT_EQ("TouchStart GestureFlingCancel GestureTapDown", ExpectedEvents());
+  EXPECT_EQ("TouchStart GestureTapDown", ExpectedEvents());
   MouseDrag(300, 300);
   EXPECT_EQ(
       "TouchMove GestureTapCancel GestureScrollBegin GestureScrollUpdate",