Rewrite references to "wtf/" to "platform/wtf/" in core/editing.

third_party/WebKit/Source/core/editing/EditingCommandTest.cpp

 // Copyright (c) 2016 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 "core/editing/EditingTestBase.h"
 #include "core/editing/Editor.h"
 #include "core/editing/commands/EditorCommandNames.h"
 #include "core/frame/LocalFrame.h"
+#include "platform/wtf/StringExtras.h"
 #include "public/platform/WebEditingCommandType.h"
-#include "wtf/StringExtras.h"
 
 namespace blink {
 
 namespace {
 
 struct CommandNameEntry {
   const char* name;
   WebEditingCommandType type;
 };
 
@@ skipping 47 matching lines @@
       "", "iNvAlId", "12345",
   };
   Editor& dummy_editor = GetDocument().GetFrame()->GetEditor();
   for (const auto& command_name : kInvalidCommandName) {
     Editor::Command command = dummy_editor.CreateCommand(command_name);
     EXPECT_EQ(0, command.IdForHistogram());
   }
 }
 
 }  // namespace blink