WTF::notFound looks too much like a local variable.

Source/core/platform/image-decoders/gif/GIFImageDecoderTest.cpp

Index: Source/core/platform/image-decoders/gif/GIFImageDecoderTest.cpp
diff --git a/Source/core/platform/image-decoders/gif/GIFImageDecoderTest.cpp b/Source/core/platform/image-decoders/gif/GIFImageDecoderTest.cpp
index c8f0263d2b77a0a252180019dbd6de3762122d8a..903d645bac7580ff52028ed7e19e48249e4f78a7 100644
--- a/Source/core/platform/image-decoders/gif/GIFImageDecoderTest.cpp
+++ b/Source/core/platform/image-decoders/gif/GIFImageDecoderTest.cpp
@@ -393,14 +393,14 @@ TEST(GIFImageDecoderTest, updateRequiredPreviousFrameAfterFirstDecode)
         ++partialSize;
     } while (!decoder->frameCount() || decoder->frameBufferAtIndex(0)->status() == ImageFrame::FrameEmpty);
 
-    EXPECT_EQ(notFound, decoder->frameBufferAtIndex(0)->requiredPreviousFrameIndex());
+    EXPECT_EQ(kNotFound, decoder->frameBufferAtIndex(0)->requiredPreviousFrameIndex());
     unsigned frameCount = decoder->frameCount();
     for (size_t i = 1; i < frameCount; ++i)
         EXPECT_EQ(i - 1, decoder->frameBufferAtIndex(i)->requiredPreviousFrameIndex());
 
     decoder->setData(fullData.get(), true);
     for (size_t i = 0; i < frameCount; ++i)
-        EXPECT_EQ(notFound, decoder->frameBufferAtIndex(i)->requiredPreviousFrameIndex());
+        EXPECT_EQ(kNotFound, decoder->frameBufferAtIndex(i)->requiredPreviousFrameIndex());
 }
 
 TEST(GIFImageDecoderTest, randomFrameDecode)
@@ -444,7 +444,7 @@ TEST(GIFImageDecoderTest, resumePartialDecodeAfterClearFrameBufferCache)
     EXPECT_EQ(frameCount, decoder->frameCount());
     ImageFrame* lastFrame = decoder->frameBufferAtIndex(frameCount - 1);
     EXPECT_EQ(baselineHashes[frameCount - 1], hashSkBitmap(lastFrame->getSkBitmap()));
-    decoder->clearCacheExceptFrame(notFound);
+    decoder->clearCacheExceptFrame(kNotFound);
 
     // Resume decoding of the first frame.
     ImageFrame* firstFrame = decoder->frameBufferAtIndex(0);