Allow left clicks in the tab strip to initiate a drag of the window.

chrome/browser/gtk/tabs/tab_strip_gtk.cc

 // 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.
 
 #include "chrome/browser/gtk/tabs/tab_strip_gtk.h"
 
 #include "app/gfx/canvas.h"
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "app/slide_animation.h"
@@ skipping 1075 matching lines @@
   // reproduce this behavior.
   if (tabstrip->GetTabCount() == 1)
     tabstrip->Layout();
   else
     tabstrip->ResizeLayoutTabs();
 }
 
 // static
 gboolean TabStripGtk::OnButtonPress(GtkWidget* widget, GdkEventButton* event,
                                     TabStripGtk* tabstrip) {
-  if (3 == event->button)
+  if (1 == event->button) {
+    gtk_window_begin_move_drag(GTK_WINDOW(gtk_widget_get_toplevel(widget)),
+        event->button, event->x_root, event->y_root, event->time);
+  } else if (3 == event->button) {
     tabstrip->ShowContextMenu();
+  }
 
   return TRUE;
 }
 
 // static
 void TabStripGtk::OnNewTabClicked(GtkWidget* widget, TabStripGtk* tabstrip) {
   tabstrip->model_->delegate()->AddBlankTab(true);
 }
 
 void TabStripGtk::PaintBackground(GdkEventExpose* event) {
@@ skipping 69 matching lines @@
 
     case TabStripModel::CommandTaskManager:
       // TODO(tc): This needs to be implemented in the TabStripModelDelegate.
       NOTIMPLEMENTED();
       break;
 
     default:
       NOTREACHED();
   }
 }