ToplevelWindowEventHandler::HandleMousePressed() has some comments about only...

ToplevelWindowEventHandler::HandleMousePressed() has some comments about only handling events post target. Those comments are untrue so remove them.
It is also non trivial to get the originally desired behavior, namely getting mouse events to HTML elements with the "-webkit-app-region" CSS style applied. 

BUG=None
TEST=None

Review URL: https://codereview.chromium.org/108723008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243439 0039d316-1c4b-4281-b951-d872f2087c98

ash/wm/toplevel_window_event_handler.cc

@@ -386,9 +386,7 @@ void ToplevelWindowEventHandler::CompleteDrag(DragCompletionStatus status) {
 void ToplevelWindowEventHandler::HandleMousePressed(
     aura::Window* target,
     ui::MouseEvent* event) {
-  // Move/size operations are initiated post-target handling to give the target
-  // an opportunity to cancel this default behavior by returning ER_HANDLED.
-  if (ui::EventCanceledDefaultHandling(*event))
+  if (event->phase() != ui::EP_PRETARGET)
     return;
 
   // We also update the current window component here because for the

ash/wm/workspace/workspace_event_handler.cc

@@ -77,12 +77,6 @@ void WorkspaceEventHandler::OnMouseEvent(ui::MouseEvent* event) {
     case ui::ET_MOUSE_EXITED:
       break;
     case ui::ET_MOUSE_PRESSED: {
-      // Maximize behavior is implemented as post-target handling so the target
-      // can cancel it.
-      if (ui::EventCanceledDefaultHandling(*event)) {
-        ToplevelWindowEventHandler::OnMouseEvent(event);
-        return;
-      }
       wm::WindowState* target_state = wm::GetWindowState(target);
       if (event->flags() & ui::EF_IS_DOUBLE_CLICK &&
           event->IsOnlyLeftMouseButton() &&

ui/events/event_utils.cc

@@ -16,10 +16,6 @@ namespace {
 int g_custom_event_types = ET_LAST;
 }  // namespace
 
-bool EventCanceledDefaultHandling(const Event& event) {
-  return event.phase() == EP_POSTTARGET && event.result() != ER_UNHANDLED;
-}
-
 int RegisterCustomEventType() {
   return ++g_custom_event_types;
 }

ui/events/event_utils.h

@@ -158,10 +158,6 @@ EVENTS_EXPORT uint16 GetScanCodeFromLParam(LPARAM lParam);
 EVENTS_EXPORT LPARAM GetLParamFromScanCode(uint16 scan_code);
 #endif
 
-// Returns true if default post-target handling was canceled for |event| after
-// its dispatch to its target.
-EVENTS_EXPORT bool EventCanceledDefaultHandling(const Event& event);
-
 // Registers a custom event type.
 EVENTS_EXPORT int RegisterCustomEventType();