Mac: Fix tab strip relayout bug.

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 173 matching lines @@
                           width:(CGFloat)width
                      fullscreen:(BOOL)fullscreen {
   // Nothing to do if no tab strip.
   if (![self hasTabStrip])
     return maxY;
 
   NSView* tabStripView = [self tabStripView];
   CGFloat tabStripHeight = NSHeight([tabStripView frame]);
   maxY -= tabStripHeight;
   NSRect tabStripFrame = NSMakeRect(0, maxY, width, tabStripHeight);
+  BOOL requiresRelayout = !NSEqualRects(tabStripFrame, [tabStripView frame]);
 
   // In Yosemite fullscreen, manually add the fullscreen controls to the tab
   // strip.
   BOOL addControlsInFullscreen =
       [self isInAppKitFullscreen] && base::mac::IsOSYosemiteOrLater();
 
   // Set left indentation based on fullscreen mode status.
   CGFloat leftIndent = 0;
   if (!fullscreen || addControlsInFullscreen)
     leftIndent = [[tabStripController_ class] defaultLeftIndentForControls];
-  [tabStripController_ setLeftIndentForControls:leftIndent];
+  if (leftIndent != [tabStripController_ leftIndentForControls]) {
+    [tabStripController_ setLeftIndentForControls:leftIndent];
+    requiresRelayout = YES;
+  }
 
   if (addControlsInFullscreen)
     [tabStripController_ addWindowControls];
   else
     [tabStripController_ removeWindowControls];
 
   // fullScreenButton is non-nil when isInAnyFullscreenMode is NO, and OS
   // version is in the range 10.7 <= version <= 10.9. Starting with 10.10, the
   // zoom/maximize button acts as the fullscreen button.
   NSButton* fullScreenButton =
@@ skipping 36 matching lines @@
     rightIndent = width - NSMinX([fullScreenButton frame]);
 
     if ([self shouldUseNewAvatarButton]) {
       // The new avatar button is to the left of the fullscreen button.
       // (The old avatar button is to the right).
       rightIndent += NSWidth([avatarButton frame]) + kAvatarRightOffset;
     }
   } else if ([self shouldShowAvatar]) {
     rightIndent += NSWidth([avatarButton frame]) + kAvatarRightOffset;
   }
-  [tabStripController_ setRightIndentForControls:rightIndent];
+
+  if (rightIndent != [tabStripController_ rightIndentForControls]) {
+    [tabStripController_ setRightIndentForControls:rightIndent];
+    requiresRelayout = YES;
+  }
 
   // It is undesirable to force tabs relayout when the tap strip's frame did
   // not change, because it will interrupt tab animations in progress.
   // In addition, there appears to be an AppKit bug on <10.9 where interrupting
   // a tab animation resulted in the tab frame being the animator's target
   // frame instead of the interrupting setFrame. (See http://crbug.com/415093)
-  if (!NSEqualRects(tabStripFrame, [tabStripView frame])){
+  if (requiresRelayout) {
     [tabStripView setFrame:tabStripFrame];
     [tabStripController_ layoutTabsWithoutAnimation];
   }
 
   return maxY;
 }
 
 - (BOOL)placeBookmarkBarBelowInfoBar {
   // If we are currently displaying the NTP detached bookmark bar or animating
   // to/from it (from/to anything else), we display the bookmark bar below the
@@ skipping 746 matching lines @@
 
       [CATransaction commit];
       hasAdjustedTabStripWhileEnteringAppKitFullscreen_ = YES;
     }
   } else {
     hasAdjustedTabStripWhileEnteringAppKitFullscreen_ = NO;
   }
 }
 
 @end  // @implementation BrowserWindowController(Private)