[ios] Fix omnibox baseWritingDirection and dismissal iOS11 bugs.

ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.mm

Index: ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.mm
diff --git a/ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.mm b/ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.mm
index 1180cf6b75987b1c03cfa0e5866ef4cccc57d712..d4337d580f72972a586685caf3139b158b4387a6 100644
--- a/ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.mm
+++ b/ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.mm
@@ -7,6 +7,7 @@
 #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"
 
@@ -556,15 +557,19 @@ NSString* const kOmniboxFadeAnimationKey = @"OmniboxFadeAnimation";
 
   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 {