Update some #includes in chrome/renderer/spellchecker for headers in the new Platform directory

chrome/renderer/spellchecker/spellcheck_provider_hunspell_unittest.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 <vector>
 
 #include "base/utf_string_conversions.h"
 #include "base/stl_util.h"
 #include "chrome/common/spellcheck_messages.h"
 #include "chrome/renderer/spellchecker/spellcheck_provider_test.h"
 #include "testing/gtest/include/gtest/gtest.h"
-#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebString.h"
 
 // Tests for Hunspell functionality in SpellcheckingProvider
 
 namespace {
 
 TEST_F(SpellCheckProviderTest, UsingHunspell) {
   FakeTextCheckingCompletion completion;
   provider_.RequestTextChecking(WebKit::WebString("hello"),
                                 &completion);
   EXPECT_EQ(completion.completion_count_, 1U);
@@ skipping 86 matching lines @@
   // Test that the SpellCheckProvider class sends a request when it receives a
   // Russian word.
   const wchar_t kRussianWord[] = L"\x0431\x0451\x0434\x0440\x0430";
   provider_.RequestTextChecking(WebKit::WebString(WideToUTF16(kRussianWord)),
                                 &completion);
   EXPECT_EQ(completion.completion_count_, 4U);
   EXPECT_EQ(completion.cancellation_count_, 2U);
 }
 
 }  // namespace