Move EventHandler timers to per-frame task queues.

third_party/WebKit/Source/core/input/EventHandler.cpp

Index: third_party/WebKit/Source/core/input/EventHandler.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandler.cpp b/third_party/WebKit/Source/core/input/EventHandler.cpp
index 5310a5bd9647c2fa2c37b82be06fa5f3442b2cd0..5132547896a51230305dedbc9dbddd33e068fe07 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -35,6 +35,7 @@
 #include "core/dom/DOMNodeIds.h"
 #include "core/dom/Document.h"
 #include "core/dom/DocumentUserGestureToken.h"
+#include "core/dom/TaskRunnerHelper.h"
 #include "core/dom/TouchList.h"
 #include "core/dom/shadow/FlatTreeTraversal.h"
 #include "core/dom/shadow/ShadowRoot.h"
@@ -160,24 +161,31 @@ class OptionalCursor {
   Cursor m_cursor;
 };
 
-EventHandler::EventHandler(LocalFrame* frame)
+EventHandler::EventHandler(LocalFrame& frame)
     : m_frame(frame),
-      m_selectionController(SelectionController::create(*frame)),
-      m_hoverTimer(this, &EventHandler::hoverTimerFired),
-      m_cursorUpdateTimer(this, &EventHandler::cursorUpdateTimerFired),
+      m_selectionController(SelectionController::create(frame)),
+      m_hoverTimer(TaskRunnerHelper::get(TaskType::UserInteraction, &frame),

[dcheng, 2016/11/18 06:11:37]

The spec doesn't say that this must happen on the user interaction task queue.
However,
https://html.spec.whatwg.org/multipage/webappapis.html#generic-task-sources
hints that perhaps this is the desired interaction:

The user interaction task source
This task source is used for features that react to user interaction, for
example keyboard or mouse input.

This is actually only used by fullscreen: entering fullscreen requires a user
gesture (AFAIK); exiting can be done programatically or with a user gesture as
well. Does the user interaction task source make sense?

+                   this,
+                   &EventHandler::hoverTimerFired),
+      m_cursorUpdateTimer(TaskRunnerHelper::get(TaskType::Internal, &frame),

[dcheng, 2016/11/18 06:11:37]

On the other hand, cursor updates aren't really interesting at all, so they go
in Internal.

+                          this,
+                          &EventHandler::cursorUpdateTimerFired),
       m_eventHandlerWillResetCapturingMouseEventsNode(0),
       m_shouldOnlyFireDragOverEvent(false),
       m_scrollManager(new ScrollManager(frame)),
-      m_mouseEventManager(new MouseEventManager(frame, m_scrollManager)),
-      m_keyboardEventManager(new KeyboardEventManager(frame, m_scrollManager)),
+      m_mouseEventManager(new MouseEventManager(frame, *m_scrollManager)),
+      m_keyboardEventManager(new KeyboardEventManager(frame, *m_scrollManager)),
       m_pointerEventManager(
-          new PointerEventManager(frame, m_mouseEventManager)),
+          new PointerEventManager(frame, *m_mouseEventManager)),
       m_gestureManager(new GestureManager(frame,
-                                          m_scrollManager,
-                                          m_mouseEventManager,
-                                          m_pointerEventManager,
-                                          m_selectionController)),
-      m_activeIntervalTimer(this, &EventHandler::activeIntervalTimerFired) {}
+                                          *m_scrollManager,
+                                          *m_mouseEventManager,
+                                          *m_pointerEventManager,
+                                          *m_selectionController)),
+      m_activeIntervalTimer(
+          TaskRunnerHelper::get(TaskType::UserInteraction, &frame),

[dcheng, 2016/11/18 06:11:37]

This is used when handling gesture events, so for the same reasons, the user
interaction task source seems appropriate.

+          this,
+          &EventHandler::activeIntervalTimerFired) {}
 
 DEFINE_TRACE(EventHandler) {
   visitor->trace(m_frame);
@@ -1913,7 +1921,6 @@ void EventHandler::resizeScrollableAreaDestroyed() {
 
 void EventHandler::hoverTimerFired(TimerBase*) {
   TRACE_EVENT0("input", "EventHandler::hoverTimerFired");
-  m_hoverTimer.stop();
 
   ASSERT(m_frame);
   ASSERT(m_frame->document());
@@ -1933,7 +1940,6 @@ void EventHandler::hoverTimerFired(TimerBase*) {
 
 void EventHandler::activeIntervalTimerFired(TimerBase*) {
   TRACE_EVENT0("input", "EventHandler::activeIntervalTimerFired");
-  m_activeIntervalTimer.stop();
 
   if (m_frame && m_frame->document() && m_lastDeferredTapElement) {
     // FIXME: Enable condition when http://crbug.com/226842 lands