Fix Fullscreen Animation Crash

chrome/browser/ui/cocoa/browser_window_controller.mm

Index: chrome/browser/ui/cocoa/browser_window_controller.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_controller.mm b/chrome/browser/ui/cocoa/browser_window_controller.mm
index 7eec24016ad9f688415a3dc6ada8a55fd97fe9f0..a91b1905a113dffecb32551516f72a69cbf4ba92 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller.mm
@@ -458,6 +458,13 @@ void SetUpBrowserWindowCommandHandler(NSWindow* window) {
   [presentationModeController_ exitPresentationMode];
   presentationModeController_.reset();
 
+  // Explicitly release |fullscreenTransition_| here since it may call back to
+  // this BWC in |-dealloc|. Reset the fullscreen variables.
+  if (fullscreenTransition_) {
+    [self resetCustomAppKitFullscreenVariables];
+    fullscreenTransition_.reset();

[Robert Sesek, 2016/04/01 20:04:05]

resetCustomAppKitFullscreenVariables does this too. But does this stop the
animation? Doesn't the CAAnimation hold a reference to the Transition object,
meaning that the Transition won't actually be dealloc'd here (until the
animation ends)?

[spqchan, 2016/04/04 16:36:16]

That's a good point, I removed all the animations from the layers before
reseting it.

I've been trying simulating the bug by killing the browser process during the
fullscreen transition and etc, but it doesn't seem like the most reliable way to
do it. Is there are good way for me to simulate this? Thanks!

+  }
+
   // Under certain testing configurations we may not actually own the browser.
   if (ownsBrowser_ == NO)
     ignore_result(browser_.release());