[Mac] Retain location bar focus on switching to fullscreen and back.

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>
 
 #import "base/auto_reset.h"
 #include "base/command_line.h"
@@ skipping 993 matching lines @@
   if ([[self.chromeContentView subviews] isEqual:subviews])
     return;
 
   // The tabContentArea isn't a subview, so just set all the subviews.
   NSView* tabContentArea = [self tabContentArea];
   if (![[self.chromeContentView subviews] containsObject:tabContentArea]) {
     [self.chromeContentView setSubviews:subviews];
     return;
   }
 
+  // Removing the location bar from the window causes it to resign first
+  // responder. Remember the location bar's focus state in order to restore
+  // it before returning.
+  BOOL locationBarHadFocus = [toolbarController_ locationBarHasFocus];
+  FullscreenToolbarVisibilityLockController* visibilityLockController = nil;
+  if (locationBarHadFocus) {
+    // The location bar, by being focused, has a visibility lock on the toolbar,
+    // and the location bar's removal from the view hierarchy will allow the
+    // toolbar to hide. Create a temporary visibility lock on the toolbar for
+    // the duration of the view hierarchy change.
+    visibilityLockController = [self fullscreenToolbarVisibilityLockController];
+    [visibilityLockController lockToolbarVisibilityForOwner:self
+                                              withAnimation:NO];
+  }
+
   // Remove all subviews that aren't the tabContentArea.
   for (NSView* view in [[[self.chromeContentView subviews] copy] autorelease]) {
     if (view != tabContentArea)
       [view removeFromSuperview];
   }
 
   // Add in the subviews below the tabContentArea.
   NSInteger index = [subviews indexOfObject:tabContentArea];
   for (int i = index - 1; i >= 0; --i) {
     NSView* view = [subviews objectAtIndex:i];
     [self.chromeContentView addSubview:view
                             positioned:NSWindowBelow
                             relativeTo:nil];
   }
 
   // Add in the subviews above the tabContentArea.
   for (NSUInteger i = index + 1; i < [subviews count]; ++i) {
     NSView* view = [subviews objectAtIndex:i];
     [self.chromeContentView addSubview:view
                             positioned:NSWindowAbove
                             relativeTo:nil];
   }
+
+  // Restore the location bar's focus state and remove the temporary visibility
+  // lock.
+  if (locationBarHadFocus) {
+    [self focusLocationBar:YES];
+    [visibilityLockController releaseToolbarVisibilityForOwner:self
+                                                 withAnimation:NO];
+  }
 }
 
 + (BOOL)systemSettingsRequireMavericksAppKitFullscreenHack {
   if (!base::mac::IsOS10_9())
     return NO;
   return [NSScreen respondsToSelector:@selector(screensHaveSeparateSpaces)] &&
          [NSScreen screensHaveSeparateSpaces];
 }
 
 - (BOOL)shouldUseMavericksAppKitFullscreenHack {
@@ skipping 140 matching lines @@
   if (fullscreenLowPowerCoordinator_)
     fullscreenLowPowerCoordinator_->SetHasActiveSheet(false);
 }
 
 - (void)childWindowsDidChange {
   if (fullscreenLowPowerCoordinator_)
     fullscreenLowPowerCoordinator_->ChildWindowsChanged();
 }
 
 @end  // @implementation BrowserWindowController(Private)