[Mac] Allow omnibox decorations to decline mouse events.

chrome/browser/cocoa/location_bar/location_bar_decoration.h

Index: chrome/browser/cocoa/location_bar/location_bar_decoration.h
diff --git a/chrome/browser/cocoa/location_bar/location_bar_decoration.h b/chrome/browser/cocoa/location_bar/location_bar_decoration.h
index 9500e42cde494f3b3d3b0ad0af3e2a3488977ccf..51571cceae85d63e48a96e4c8d989e12708833d1 100644
--- a/chrome/browser/cocoa/location_bar/location_bar_decoration.h
+++ b/chrome/browser/cocoa/location_bar/location_bar_decoration.h
@@ -46,6 +46,13 @@ class LocationBarDecoration {
   // 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; }