[ios] Fix omnibox baseWritingDirection and dismissal iOS11 bugs.

ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.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 "ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.h"
 
 #import <CoreText/CoreText.h>
 
 #include "base/command_line.h"
+#include "base/ios/ios_util.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
 
 #include "base/strings/sys_string_conversions.h"
 #include "components/grit/components_scaled_resources.h"
 #include "components/omnibox/browser/autocomplete_input.h"
 #include "ios/chrome/browser/autocomplete/autocomplete_scheme_classifier_impl.h"
 #import "ios/chrome/browser/ui/animation_util.h"
 #include "ios/chrome/browser/ui/omnibox/omnibox_util.h"
 #import "ios/chrome/browser/ui/reversed_animation.h"
@@ skipping 529 matching lines @@
 - (void)updateTextDirection {
   // Setting the empty field to Natural seems to let iOS update the cursor
   // position when the keyboard language is changed.
   if (![self text].length) {
     [self setTextAlignment:NSTextAlignmentNatural];
     return;
   }
 
   NSTextAlignment alignment = [self bestTextAlignment];
   [self setTextAlignment:alignment];
-  UITextWritingDirection writingDirection =
-      alignment == NSTextAlignmentLeft ? UITextWritingDirectionLeftToRight
-                                       : UITextWritingDirectionRightToLeft;
-  [self
-      setBaseWritingDirection:writingDirection
-                     forRange:[self
-                                  textRangeFromPosition:[self
-                                                            beginningOfDocument]
-                                             toPosition:[self endOfDocument]]];
+  if (!base::ios::IsRunningOnIOS11OrLater()) {
+    // TODO(crbug.com/730461): Remove this entire block once it's been tested

[rohitrao (ping after 24h), 2017/06/14 14:54:11]

Can you please update the bug with a detailed description of why you think this
code is no longer necessary?  The goal is to document this for later, and also
to convince me that we don't need this code =)

[justincohen, 2017/06/14 16:44:08]

Done.

+    // on trunk.
+    UITextWritingDirection writingDirection =
+        alignment == NSTextAlignmentLeft ? UITextWritingDirectionLeftToRight
+                                         : UITextWritingDirectionRightToLeft;
+    [self
+        setBaseWritingDirection:writingDirection
+                       forRange:
+                           [self
+                               textRangeFromPosition:[self beginningOfDocument]
+                                          toPosition:[self endOfDocument]]];
+  }
 }
 
 - (void)setPlaceholder:(NSString*)placeholder {
   if (placeholder && _placeholderTextColor) {
     NSDictionary* attributes =
         @{NSForegroundColorAttributeName : _placeholderTextColor};
     self.attributedPlaceholder =
         [[NSAttributedString alloc] initWithString:placeholder
                                         attributes:attributes];
   } else {
@@ skipping 437 matching lines @@
   // Disable the RTL arrow menu item. The omnibox sets alignment based on the
   // text in the field, and should not be overridden.
   if ([NSStringFromSelector(action) hasPrefix:@"makeTextWritingDirection"]) {
     return NO;
   }
 
   return [super canPerformAction:action withSender:sender];
 }
 
 @end