Use a direct include of strings headers in ui/, part 1.

ui/base/gtk/gtk_im_context_util.cc

 // 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.
 
 #include "ui/base/gtk/gtk_im_context_util.h"
 
 #include "base/basictypes.h"
 #include "base/i18n/char_iterator.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/base/ime/composition_text.h"
 
 namespace ui {
 
 void ExtractCompositionTextFromGtkPreedit(const gchar* utf8_text,
                                           PangoAttrList* attrs,
                                           int cursor_position,
                                           CompositionText* composition) {
   composition->Clear();
@@ skipping 85 matching lines @@
   }
 
   // Use a black thin underline by default.
   if (composition->underlines.empty()) {
     composition->underlines.push_back(
         CompositionUnderline(0, length, SK_ColorBLACK, false));
   }
 }
 
 }  // namespace ui