Do not close the omnibox popup on mouseDown.

chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.mm

 // Copyright (c) 2011 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 "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.h"
 
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"  // IDC_*
 #include "chrome/browser/ui/browser_list.h"
@@ skipping 450 matching lines @@
   NSTextStorage* textStorage = [self textStorage];
   DCHECK(textStorage);
   [textStorage setAttributedString:aString];
 
   // The text has been changed programmatically. The observer should know
   // this change, so setting |textChangedByKeyEvents_| to NO to
   // prevent its OnDidChange() method from being called unnecessarily.
   textChangedByKeyEvents_ = NO;
 }
 
-- (void)mouseDown:(NSEvent*)theEvent {
-  // Close the popup before processing the event.
-  AutocompleteTextFieldObserver* observer = [self observer];
-  if (observer)
-    observer->ClosePopup();
-
-  [super mouseDown:theEvent];
-}
-
 - (BOOL)validateMenuItem:(NSMenuItem*)item {
   if ([item action] == @selector(copyToFindPboard:))
     return [self selectedRange].length > 0;
   return [super validateMenuItem:item];
 }
 
 - (void)copyToFindPboard:(id)sender {
   NSRange selectedRange = [self selectedRange];
   if (selectedRange.length == 0)
     return;
   NSAttributedString* selection =
       [self attributedSubstringForProposedRange:selectedRange
                                     actualRange:NULL];
   if (!selection)
     return;
 
   [[FindPasteboard sharedInstance] setFindText:[selection string]];
 }
 
 @end