src/: Update the remaining include paths of string_split.h to its new location.

ui/views/controls/label.cc

 // Copyright (c) 2012 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/views/controls/label.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 #include <vector>
 
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
-#include "base/string_split.h"
 #include "base/string_util.h"
+#include "base/strings/string_split.h"
 #include "base/utf_string_conversions.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/text/text_elider.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/font.h"
 #include "ui/gfx/insets.h"
 #include "ui/gfx/shadow_value.h"
 #include "ui/native_theme/native_theme.h"
@@ skipping 440 matching lines @@
         ui::NativeTheme::kColorId_LabelDisabledColor);
   }
   if (!background_color_set_) {
     background_color_ = theme->GetSystemColor(
         ui::NativeTheme::kColorId_LabelBackgroundColor);
   }
   RecalculateColors();
 }
 
 }  // namespace views