Revert of mac: Don't animate tab close when closing all tabs. (patchset #1...

Revert of mac: Don't animate tab close when closing all tabs. (patchset #1 id:1 of https://codereview.chromium.org/2598393003/ )

Reason for revert:
Causes crashes: https://bugs.chromium.org/p/chromium/issues/detail?id=677494

Original issue's description:
> mac: Don't animate tab close when closing all tabs.
>
> The animations potentially slow down shutdown, without providing positive
> utility.
>
> BUG=571908
>
> Review-Url: https://codereview.chromium.org/2598393003

TBR=asvitkine@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=571908

Review-Url: https://codereview.chromium.org/2605313002
Cr-Commit-Position: refs/heads/master@{#440972}

chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm

@@ -1514,7 +1514,7 @@ NSRect FlipRectInView(NSView* view, NSRect rect) {
   hoverTabSelector_->CancelTabTransition();
 
   TabController* tab = [tabArray_ objectAtIndex:index];
-  if (tabStripModel_->count() > 0 && !tabStripModel_->closing_all()) {
+  if (tabStripModel_->count() > 0) {
     [self startClosingTabWithAnimation:tab];
     [self layoutTabs];
   } else {