Do not close the omnibox popup on mouseDown.

chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.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.h"
 
 #include "base/logging.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #import "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_cell.h"
 #import "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.h"
@@ skipping 60 matching lines @@
 // field editor area, and if so sets the selection to {0,0} to clear
 // the selection before forwarding the event to the field editor for
 // processing (it will set the cursor position).  This also starts the
 // click-drag selection machinery.
 //
 // This code does the same thing for cases where the click was in the
 // decoration area.  This allows the user to click-drag starting from
 // a decoration area and get the expected selection behaviour,
 // likewise for multiple clicks in those areas.
 - (void)mouseDown:(NSEvent*)theEvent {
-  // Close the popup before processing the event.  This prevents the
-  // popup from being visible while a right-click context menu or
-  // page-action menu is visible.  Also, it matches other platforms.
-  if (observer_)
-    observer_->ClosePopup();
-
   // If the click was a Control-click, bring up the context menu.
   // |NSTextField| handles these cases inconsistently if the field is
   // not already first responder.
   if (([theEvent modifierFlags] & NSControlKeyMask) != 0) {
     NSText* editor = [self currentEditor];
     NSMenu* menu = [editor menuForEvent:theEvent];
     [NSMenu popUpContextMenu:menu withEvent:theEvent forView:editor];
     return;
   }
 
@@ skipping 286 matching lines @@
 - (NSMenu*)decorationMenuForEvent:(NSEvent*)event {
   AutocompleteTextFieldCell* cell = [self cell];
   return [cell decorationMenuForEvent:event inRect:[self bounds] ofView:self];
 }
 
 - (ViewID)viewID {
   return VIEW_ID_LOCATION_BAR;
 }
 
 @end