Mac: Speculative fix for tracking area crashes

ui/base/cocoa/base_view.h

Index: ui/base/cocoa/base_view.h
diff --git a/ui/base/cocoa/base_view.h b/ui/base/cocoa/base_view.h
index 642ada2011d0812a58ed8c8ace2895b803b850cf..26e2fd63201f22f35c558a19ea3e6f7118f40663 100644
--- a/ui/base/cocoa/base_view.h
+++ b/ui/base/cocoa/base_view.h
@@ -28,8 +28,15 @@ UI_BASE_EXPORT
   ui::ScopedCrTrackingArea trackingArea_;
   BOOL dragging_;
   base::scoped_nsobject<NSEvent> pendingExitEvent_;
+  id eventTap_;
 }
 
+// NSTrackingInVisibleRect doesn't work correctly with Lion's window resizing,
+// http://crbug.com/176725 / http://openradar.appspot.com/radar?id=2773401 .
+// Setting |useEventTap| to YES will avoid using the tracking area for mouse
+// moved handling, and will instead tap it from the application's event stream.
+- (instancetype)initWithFrame:(NSRect)frame useEventTap:(BOOL)useEventTap;

[Nico, 2015/02/26 22:16:07]

Should this be named by intent rather by workaround? ("needMouseMoveEvents:")

[Andre, 2015/02/26 22:29:58]

Mouse moved events are enabled either way, using a tracking area when NO, and
using an event
tap if YES. So calling it needMouseMoveEvents doesn't seem right.
An option is to always use an event tap for mouse moved events, then won't need
this parameter,
but that might be too big/risky of a change since we only need this workaround
when the view
is positioned on the bottom left corner of the window.

[Nico, 2015/02/26 23:43:24]

needReliableMouseMoveEvents? :-)

[Andre, 2015/02/27 00:05:49]

Sounds good, went with wantsReliableMouseEvents.
PTAL.

+
 // Override these methods (mouseEvent, keyEvent) in a subclass.
 - (void)mouseEvent:(NSEvent *)theEvent;