mac: Fix tab dragging visual bug in Yosemite.

chrome/browser/ui/cocoa/browser_window_controller_private.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/browser_window_controller_private.h"
 
 #include <cmath>
 
 #include "base/command_line.h"
 #include "base/mac/mac_util.h"
@@ skipping 549 matching lines @@
   [self disableBarVisibilityUpdates];
 
   // Retain the tab strip view while we remove it from its superview.
   base::scoped_nsobject<NSView> tabStripView;
   if ([self hasTabStrip]) {
     tabStripView.reset([[self tabStripView] retain]);
     [tabStripView removeFromSuperview];
   }
 
   // Ditto for the content view.
-  base::scoped_nsobject<NSView> contentView(
-      [[sourceWindow contentView] retain]);
+  base::scoped_nsobject<NSView> contentView([self.chromeContentView retain]);

[Scott Hess - ex-Googler, 2014/07/11 18:08:34]

Previously, |contentView| was essential because -removeFromSuperview would
remove the last reference.  Now chromeContentView_ should still contain a ref (I
think), so could the below just s/contentView/chromeContentView_/ ?

[erikchen, 2014/07/11 20:48:04]

I removed the local variable.

   // Disable autoresizing of subviews while we move views around. This prevents
   // spurious renderer resizes.
   [contentView setAutoresizesSubviews:NO];
   [contentView removeFromSuperview];
 
   // Have to do this here, otherwise later calls can crash because the window
   // has no delegate.
   [sourceWindow setDelegate:nil];
   [destWindow setDelegate:self];
 
   // With this call, valgrind complains that a "Conditional jump or move depends
   // on uninitialised value(s)".  The error happens in -[NSThemeFrame
   // drawOverlayRect:].  I'm pretty convinced this is an Apple bug, but there is
   // no visual impact.  I have been unable to tickle it away with other window
   // or view manipulation Cocoa calls.  Stack added to suppressions_mac.txt.
   [contentView setAutoresizesSubviews:YES];
-  [destWindow setContentView:contentView];
+  [[destWindow contentView] addSubview:contentView
+                            positioned:NSWindowBelow
+                            relativeTo:nil];
 
   // Move the incognito badge if present.
   if ([self shouldShowAvatar]) {
     NSView* avatarButtonView = [avatarButtonController_ view];
 
     [avatarButtonView removeFromSuperview];
     [avatarButtonView setHidden:YES];  // Will be shown in layout.
     [[destWindow cr_windowView] addSubview:avatarButtonView];
   }
 
@@ skipping 246 matching lines @@
 
 - (void)windowDidEnterFullScreen:(NSNotification*)notification {
   // In Yosemite, some combination of the titlebar and toolbar always show in
   // full-screen mode. We do not want either to show. Search for the window that
   // contains the views, and hide it. There is no need to ever unhide the view.
   // http://crbug.com/380235
   if (base::mac::IsOSYosemiteOrLater()) {
     for (NSWindow* window in [[NSApplication sharedApplication] windows]) {
       if ([window
               isKindOfClass:NSClassFromString(@"NSToolbarFullScreenWindow")]) {
-        [window.contentView setHidden:YES];
+        [[window contentView] setHidden:YES];
       }
     }
   }
 
   if (notification)  // For System Fullscreen when non-nil.
     [self deregisterForContentViewResizeNotifications];
   enteringFullscreen_ = NO;
   enteringPresentationMode_ = NO;
 
   const CommandLine* command_line = CommandLine::ForCurrentProcess();
@@ skipping 57 matching lines @@
 
   barVisibilityUpdatesEnabled_ = NO;
   [presentationModeController_ cancelAnimationAndTimers];
 }
 
 - (CGFloat)toolbarDividerOpacity {
   return [bookmarkBarController_ toolbarDividerOpacity];
 }
 
 - (void)updateSubviewZOrder:(BOOL)inPresentationMode {
-  NSView* contentView = [[self window] contentView];
+  NSView* contentView = self.chromeContentView;
   NSView* toolbarView = [toolbarController_ view];
 
   if (inPresentationMode) {
     // Toolbar is above tab contents so that it can slide down from top of
     // screen.
     [contentView cr_ensureSubview:toolbarView
                      isPositioned:NSWindowAbove
                        relativeTo:[self tabContentArea]];
   } else {
     // Toolbar is below tab contents so that the info bar arrow can appear above
@@ skipping 82 matching lines @@
     devTools->SetAllowOverlappingViews(allowOverlappingViews);
 }
 
 - (void)updateInfoBarTipVisibility {
   // If there's no toolbar then hide the infobar tip.
   [infoBarContainerController_
       setShouldSuppressTopInfoBarTip:![self hasToolbar]];
 }
 
 @end  // @implementation BrowserWindowController(Private)