[ios] Remove the openJavascript method from Tab.

ios/chrome/browser/ui/browser_view_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/chrome/browser/ui/browser_view_controller.h"
 
 #import <AssetsLibrary/AssetsLibrary.h>
 #import <MobileCoreServices/MobileCoreServices.h>
 #import <PassKit/PassKit.h>
 #import <Photos/Photos.h>
@@ skipping 3769 matching lines @@
       inBackground:inBackground
           appendTo:kLastTab]);
   [self chromeExecuteCommand:command];
 }
 
 - (void)loadSessionTab:(const sessions::SessionTab*)sessionTab {
   [[_model currentTab] loadSessionTab:sessionTab];
 }
 
 - (void)openJavascript:(NSString*)javascript {
-  [[_model currentTab] openJavascript:javascript];
+  DCHECK(javascript);
+  javascript = [javascript stringByRemovingPercentEncoding];

[rohitrao (ping after 24h), 2017/01/19 21:59:09]

Is this sanitization important?

[Eugene But (OOO till 7-30), 2017/01/19 22:20:33]

I don't know.

+  web::WebState* web_state = [[_model currentTab] webState];

[Eugene But (OOO till 7-30), 2017/01/19 22:20:34]

s/web_state/webState

[rohitrao (ping after 24h), 2017/01/20 16:12:17]

Done.

+  if (web_state) {
+    web_state->ExecuteJavaScript(base::SysNSStringToUTF16(javascript));

[rohitrao (ping after 24h), 2017/01/19 21:59:09]

This is a little dumb because we go from UTF8 -> NSString -> UTF16 -> NSString
=)  I can probably remove one of those conversions.

[Eugene But (OOO till 7-30), 2017/01/19 22:20:33]

This is user supplied JS. I don't think they can type so much code to cause a
performance problem :)

[rohitrao (ping after 24h), 2017/01/20 16:12:17]

This is not actually true.  The JS supplied here comes from links in the page,
so they can probably be arbitrarily large.

[Eugene But (OOO till 7-30), 2017/01/20 18:05:18]

So maybe we should change WebState::ExecuteJavaScript to take NSString? I
created this method with sting16 signature to match content API, but in this
case it looks like diverging is reasonable.

+  }
 }
 
 #pragma mark - WebToolbarDelegate methods
 
 - (IBAction)locationBarDidBecomeFirstResponder:(id)sender {
   if (_locationBarHasFocus)
     return;  // TODO(crbug.com/244366): This should not be necessary.
   _locationBarHasFocus = YES;
   [[NSNotificationCenter defaultCenter]
       postNotificationName:ios_internal::
@@ skipping 1333 matching lines @@
 
 - (UIView*)voiceSearchButton {
   return _voiceSearchButton;
 }
 
 - (id<LogoAnimationControllerOwner>)logoAnimationControllerOwner {
   return [self currentLogoAnimationControllerOwner];
 }
 
 @end