Fix mouse cursor update timer to be page-global instead of per-frame

Source/core/page/EventHandler.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 313 matching lines @@
     m_eventHandlerWillResetCapturingMouseEventsNode = false;
     m_mouseDownWasSingleClickInSelection = false;
     m_selectionInitiationState = HaveNotStartedSelection;
     m_mouseDownMayStartAutoscroll = false;
     m_svgPan = false;
     m_mouseDownPos = IntPoint();
     m_mouseDownTimestamp = 0;
     m_longTapShouldInvokeContextMenu = false;
     m_dragStartPos = LayoutPoint();
     m_offsetFromResizeCorner = LayoutSize();
-    m_currentMouseCursor = Cursor();
     m_mouseDown = PlatformMouseEvent();
-
 }
 
 void EventHandler::nodeWillBeRemoved(Node& nodeToBeRemoved)
 {
     if (nodeToBeRemoved.containsIncludingShadowDOM(m_clickNode.get())) {
         // We don't dispatch click events if the mousedown node is removed
         // before a mouseup event. It is compatible with IE and Firefox.
         m_clickNode = nullptr;
     }
 }
@@ skipping 693 matching lines @@
 void EventHandler::cursorUpdateTimerFired(Timer<EventHandler>*)
 {
     ASSERT(m_frame);
     ASSERT(m_frame->document());
 
     updateCursor();
 }
 
 void EventHandler::updateCursor()
 {
+    // We must do a cross-frame hit test because the frame that triggered the cursor
+    // update could be occluded by a different frame.
+    ASSERT(m_frame == m_frame->localFrameRoot());
+
     if (m_mousePositionIsUnknown)
         return;
 
     FrameView* view = m_frame->view();
     if (!view || !view->shouldSetCursor())
         return;
 
     LayoutView* layoutView = view->layoutView();
     if (!layoutView)
         return;
 
     m_frame->document()->updateLayout();
 
-    HitTestRequest request(HitTestRequest::ReadOnly);
+    HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::AllowChildFrameContent);
     HitTestResult result(request, view->rootFrameToContents(m_lastKnownMousePosition));
     layoutView->hitTest(result);
 
-    OptionalCursor optionalCursor = selectCursor(result);
-    if (optionalCursor.isCursorChange()) {
-        m_currentMouseCursor = optionalCursor.cursor();
-        view->setCursor(m_currentMouseCursor);
+    if (LocalFrame* frame = result.innerNodeFrame()) {
+        OptionalCursor optionalCursor = frame->eventHandler().selectCursor(result);
+        if (optionalCursor.isCursorChange()) {
+            view->setCursor(optionalCursor.cursor());
+        }
     }
 }
 
 OptionalCursor EventHandler::selectCursor(const HitTestResult& result)
 {
     if (m_resizeScrollableArea && m_resizeScrollableArea->inResizeMode())
         return NoCursorChange;
 
     Page* page = m_frame->page();
     if (!page)
         return NoCursorChange;
-#if OS(WIN)
     if (panScrollInProgress())
         return NoCursorChange;
-#endif
 
     Node* node = result.innerPossiblyPseudoNode();
     if (!node)
         return selectAutoCursor(result, node, iBeamCursor());
 
     LayoutObject* renderer = node->layoutObject();
     const ComputedStyle* style = renderer ? renderer->style() : nullptr;
 
     if (renderer) {
         Cursor overrideCursor;
@@ skipping 417 matching lines @@
         // Event dispatch in updateMouseEventTargetNode may have caused the subframe of the target
         // node to be detached from its FrameView, in which case the event should not be passed.
         if (newSubframe->view())
             swallowEvent |= passMouseMoveEventToSubframe(mev, newSubframe.get(), hoveredNode);
     } else {
         if (scrollbar && !m_mousePressed)
             scrollbar->mouseMoved(mouseEvent); // Handle hover effects on platforms that support visual feedback on scrollbar hovering.
         if (FrameView* view = m_frame->view()) {
             OptionalCursor optionalCursor = selectCursor(mev.hitTestResult());
             if (optionalCursor.isCursorChange()) {
-                m_currentMouseCursor = optionalCursor.cursor();
-                view->setCursor(m_currentMouseCursor);
+                view->setCursor(optionalCursor.cursor());
             }
         }
     }
 
     m_lastMouseMoveEventSubframe = newSubframe;
 
     if (swallowEvent)
         return true;
 
     swallowEvent = !dispatchMouseEvent(EventTypeNames::mousemove, mev.innerNode(), 0, mouseEvent, true);
@@ skipping 1592 matching lines @@
 }
 
 void EventHandler::scheduleHoverStateUpdate()
 {
     if (!m_hoverTimer.isActive())
         m_hoverTimer.startOneShot(0, FROM_HERE);
 }
 
 void EventHandler::scheduleCursorUpdate()
 {
+    // We only want one timer for the page, rather than each frame having it's own timer
+    // competing which eachother (since there's only one mouse cursor).
+    ASSERT(m_frame == m_frame->localFrameRoot());
+
     if (!m_cursorUpdateTimer.isActive())
         m_cursorUpdateTimer.startOneShot(cursorUpdateInterval, FROM_HERE);
 }
 
 void EventHandler::dispatchFakeMouseMoveEventSoon()
 {
     if (m_mousePressed)
         return;
 
     if (m_mousePositionIsUnknown)
@@ skipping 988 matching lines @@
 unsigned EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return PlatformEvent::CtrlKey | PlatformEvent::AltKey;
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace blink