Add a inner text parameter to ContextMenuParams

ios/web/web_state/ui/crw_web_controller.mm

 // Copyright 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 "ios/web/web_state/ui/crw_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 4272 matching lines @@
   if (titleAttribute)
     title = titleAttribute;
   if (title) {
     params.menu_title.reset([title copy]);
   }
   NSString* referrerPolicy = element[@"referrerPolicy"];
   if (referrerPolicy) {
     params.referrer_policy =
         web::ReferrerPolicyFromString(base::SysNSStringToUTF8(referrerPolicy));
   }
+  NSString* innerText = element[@"innerText"];

[marq (ping after 24h), 2016/10/03 11:31:09]

If the JS innerText value is an empty string, what is the behavior here? Is
|innerText| null or an empty NSString? And what is the expected behavior of code
that uses the params struct?

(Ideally document in the params struct header whether the string can be empty or
not). 

[gambard, 2016/10/03 12:05:52]

The string can be empty or potentially nil (if the HTML element is not a <a/>).
Done.

+  if (innerText) {
+    params.inner_text.reset([innerText copy]);
+  }
   return params;
 }
 
 #pragma mark -
 #pragma mark Fullscreen
 
 - (CGRect)visibleFrame {
   CGRect frame = [_containerView bounds];
   CGFloat headerHeight = [self headerHeight];
   frame.origin.y = headerHeight;
@@ skipping 1326 matching lines @@
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end