[Mac] Allow omnibox decorations to decline mouse events.

chrome/browser/cocoa/location_bar/location_bar_decoration.h

 // Copyright (c) 2010 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.
 
 #ifndef CHROME_BROWSER_COCOA_LOCATION_BAR_LOCATION_BAR_DECORATION_H_
 #define CHROME_BROWSER_COCOA_LOCATION_BAR_LOCATION_BAR_DECORATION_H_
 
 #import <Cocoa/Cocoa.h>
 
 #import "base/basictypes.h"
@@ skipping 28 matching lines @@
   // or |kOmittedWidth| if it should be omitted.
   virtual CGFloat GetWidthForSpace(CGFloat width);
 
   // Draw the decoration in the frame provided.  The frame will be
   // generated from an earlier call to |GetWidthForSpace()|.
   virtual void DrawInFrame(NSRect frame, NSView* control_view);
 
   // Returns the tooltip for this decoration, return |nil| for no tooltip.
   virtual NSString* GetToolTip() { return nil; }
 
+  // Decorations which do not accept mouse events are treated like the
+  // field's background for purposes of selecting text.  When such
+  // decorations are adjacent to the text area, they will show the
+  // I-beam cursor.  Decorations which do accept mouse events will get
+  // an arrow cursor when the mouse is over them.
+  virtual bool AcceptsMousePress() { return false; }
+
   // Determine if the item can act as a drag source.
   virtual bool IsDraggable() { return false; }
 
   // The image to drag.
   virtual NSImage* GetDragImage() { return nil; }
 
   // The pasteboard to drag.
   virtual NSPasteboard* GetDragPasteboard() { return nil; }
 
   // Called on mouse down.  Return |false| to indicate that the press
   // was not processed and should be handled by the cell.
   virtual bool OnMousePressed(NSRect frame) { return false; }
 
   // Called to get the right-click menu, return |nil| for no menu.
   virtual NSMenu* GetMenu() { return nil; }
 
   // Width returned by |GetWidthForSpace()| when the item should be
   // omitted for this width;
   static const CGFloat kOmittedWidth;
 
  private:
   bool visible_;
 
   DISALLOW_COPY_AND_ASSIGN(LocationBarDecoration);
 };
 
 #endif  // CHROME_BROWSER_COCOA_LOCATION_BAR_LOCATION_BAR_DECORATION_H_