Use BlobCallback in toBlob instead of FileCallback

third_party/WebKit/Source/core/core.gypi

 {
     'includes': [
         'core_generated.gypi',
     ],
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/KeyframeEffect.idl',
             'animation/EffectModel.idl',
             'animation/AnimationEffectReadOnly.idl',
@@ skipping 126 matching lines @@
             'events/RelatedEvent.idl',
             'events/ResourceProgressEvent.idl',
             'events/SecurityPolicyViolationEvent.idl',
             'events/TextEvent.idl',
             'events/TouchEvent.idl',
             'events/TransitionEvent.idl',
             'events/UIEvent.idl',
             'events/WheelEvent.idl',
             'fileapi/Blob.idl',
             'fileapi/File.idl',
-            'fileapi/FileCallback.idl',
+            'fileapi/BlobCallback.idl',
             'fileapi/FileError.idl',
             'fileapi/FileList.idl',
             'fileapi/FileReader.idl',
             'fileapi/FileReaderSync.idl',
             'frame/BarProp.idl',
             'frame/Console.idl',
             'frame/ConsoleBase.idl',
             'frame/History.idl',
             'frame/ImageBitmap.idl',
             'frame/Location.idl',
@@ skipping 1411 matching lines @@
             'fetch/UniqueIdentifier.cpp',
             'fetch/UniqueIdentifier.h',
             'fetch/WebCacheMemoryDumpProvider.cpp',
             'fetch/WebCacheMemoryDumpProvider.h',
             'fetch/XSLStyleSheetResource.cpp',
             'fetch/XSLStyleSheetResource.h',
             'fileapi/Blob.cpp',
             'fileapi/Blob.h',
             'fileapi/File.cpp',
             'fileapi/File.h',
-            'fileapi/FileCallback.h',
+            'fileapi/BlobCallback.h',
             'fileapi/FileError.cpp',
             'fileapi/FileError.h',
             'fileapi/FileList.cpp',
             'fileapi/FileList.h',
             'fileapi/FileReader.cpp',
             'fileapi/FileReader.h',
             'fileapi/FileReaderLoader.cpp',
             'fileapi/FileReaderLoader.h',
             'fileapi/FileReaderLoaderClient.h',
             'fileapi/FileReaderSync.cpp',
@@ skipping 2445 matching lines @@
             'style/SVGComputedStyleTest.cpp',
             'svg/SVGPathParserTest.cpp',
             'svg/UnsafeSVGAttributeSanitizationTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'timing/MemoryInfoTest.cpp',
             'workers/WorkerThreadTest.cpp',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }