Fix a few issues with the drop arrow in the Linux tab strip:...

chrome/browser/gtk/tabs/tab_strip_gtk.h

 // Copyright (c) 2009 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_GTK_TABS_TAB_STRIP_GTK_H_
 #define CHROME_BROWSER_GTK_TABS_TAB_STRIP_GTK_H_
 
 #include <gtk/gtk.h>
 #include <vector>
 
@@ skipping 289 matching lines @@
   // it.
   gfx::Rect GetDropBounds(int drop_index, bool drop_before, bool* is_beneath);
 
   // Updates the location of the drop based on the event.
   void UpdateDropIndex(GdkDragContext* context, gint x, gint y);
 
   // Sets the location of the drop, repainting as necessary.
   void SetDropIndex(int index, bool drop_before);
 
   // Determines whether the data is acceptable by the tabstrip and opens a new
-  // tab with the data as URL if it is.
-  void CompleteDrop(guchar* data);
+  // tab with the data as URL if it is.  Returns true if the drop was
+  // successful.
+  bool CompleteDrop(guchar* data);
 
   // Returns the image to use for indicating a drop on a tab. If is_down is
   // true, this returns an arrow pointing down.
   static GdkPixbuf* GetDropArrowImage(bool is_down);
 
   // -- Animations -------------------------------------------------------------
 
   // A generic Layout method for various classes of TabStrip animations,
   // including Insert, Remove and Resize Layout cases.
   void AnimationLayout(double unselected_width);
@@ skipping 78 matching lines @@
   // ResizeLayoutTabsNow method.
   ScopedRunnableMethodFactory<TabStripGtk> resize_layout_factory_;
 
   // True if the tabstrip has already been added as a MessageLoop observer.
   bool added_as_message_loop_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(TabStripGtk);
 };
 
 #endif  // CHROME_BROWSER_GTK_TABS_TAB_STRIP_GTK_H_