Rewrite references to "wtf/" to "platform/wtf/" in platform/graphics.

third_party/WebKit/Source/platform/graphics/paint/PaintChunkTest.cpp

 // Copyright 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 "platform/graphics/paint/PaintChunk.h"
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/testing/FakeDisplayItemClient.h"
+#include "platform/wtf/Optional.h"
 #include "testing/gtest/include/gtest/gtest.h"
-#include "wtf/Optional.h"
 
 namespace blink {
 
 TEST(PaintChunkTest, matchesSame) {
   PaintChunkProperties properties;
   FakeDisplayItemClient client;
   client.updateCacheGeneration();
   DisplayItem::Id id(client, DisplayItem::kDrawingFirst);
   EXPECT_TRUE(PaintChunk(0, 1, &id, properties)
                   .matches(PaintChunk(0, 1, &id, properties)));
@@ skipping 65 matching lines @@
 
   // Delete the current object and create a new object at the same address.
   client = WTF::nullopt;
   client.emplace();
   EXPECT_TRUE(client->isJustCreated());
   EXPECT_FALSE(PaintChunk(0, 1, &id, properties)
                    .matches(PaintChunk(0, 1, &id, properties)));
 }
 
 }  // namespace blink