[Mac] Detect control-key changes in autocomplete field.

chrome/browser/cocoa/autocomplete_text_field.mm

Index: chrome/browser/cocoa/autocomplete_text_field.mm
diff --git a/chrome/browser/cocoa/autocomplete_text_field.mm b/chrome/browser/cocoa/autocomplete_text_field.mm
index 6d1d5d572e04b5f6dfaedf00c82f7863b8d7da9e..9af1b7dc85d7d7a108144d5ce3ce5cf3b397bbaa 100644
--- a/chrome/browser/cocoa/autocomplete_text_field.mm
+++ b/chrome/browser/cocoa/autocomplete_text_field.mm
@@ -25,4 +25,12 @@
   return YES;
 }
 
+- (void)flagsChanged:(NSEvent*)theEvent {
+  id delegate = [self delegate];
+  if ([delegate respondsToSelector:@selector(control:flagsChanged:)]) {
+    [delegate control:self flagsChanged:theEvent];
+  }
+  [super flagsChanged:theEvent];
+}
+
 @end