Convert string16 to base::string16 in content.

content/browser/accessibility/browser_accessibility_cocoa.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.
 
 #include <execinfo.h>
 
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 
 #include <map>
 
@@ skipping 551 matching lines @@
   return nil;
 }
 
 // Returns whether or not this node should be ignored in the
 // accessibility tree.
 - (BOOL)isIgnored {
   return [[self role] isEqualToString:NSAccessibilityUnknownRole];
 }
 
 - (NSString*)invalid {
-  string16 invalidUTF;
+  base::string16 invalidUTF;
   if (!browserAccessibility_->GetHtmlAttribute("aria-invalid", &invalidUTF))
     return NULL;
   NSString* invalid = base::SysUTF16ToNSString(invalidUTF);
   if ([invalid isEqualToString:@"false"] ||
       [invalid isEqualToString:@""]) {
     return @"false";
   }
   return invalid;
 }
 
@@ skipping 706 matching lines @@
         nil]];
   } else if ([subrole isEqualToString:NSAccessibilityOutlineRowSubrole]) {
     [ret addObjectsFromArray:[NSArray arrayWithObjects:
         NSAccessibilityDisclosingAttribute,
         NSAccessibilityDisclosedByRowAttribute,
         NSAccessibilityDisclosureLevelAttribute,
         NSAccessibilityDisclosedRowsAttribute,
         nil]];
   } else if ([role isEqualToString:NSAccessibilityRowRole]) {
     if (browserAccessibility_->parent()) {
-      string16 parentRole;
+      base::string16 parentRole;
       browserAccessibility_->parent()->GetHtmlAttribute(
           "role", &parentRole);
-      const string16 treegridRole(ASCIIToUTF16("treegrid"));
+      const base::string16 treegridRole(ASCIIToUTF16("treegrid"));
       if (parentRole == treegridRole) {
         [ret addObjectsFromArray:[NSArray arrayWithObjects:
             NSAccessibilityDisclosingAttribute,
             NSAccessibilityDisclosedByRowAttribute,
             NSAccessibilityDisclosureLevelAttribute,
             NSAccessibilityDisclosedRowsAttribute,
             nil]];
       } else {
         [ret addObjectsFromArray:[NSArray arrayWithObjects:
             NSAccessibilityIndexAttribute,
@@ skipping 162 matching lines @@
     return [super hash];
   return browserAccessibility_->renderer_id();
 }
 
 - (BOOL)accessibilityShouldUseUniqueId {
   return YES;
 }
 
 @end