Sync Blob.close() behavior wrt updated spec.

Source/core/fileapi/File.h

Index: Source/core/fileapi/File.h
diff --git a/Source/core/fileapi/File.h b/Source/core/fileapi/File.h
index 1688f4321291ad239c8c829d9403e5733e8e1b51..bcd47fcb37166c65a96bb5f0e10c1939cbcf8d72 100644
--- a/Source/core/fileapi/File.h
+++ b/Source/core/fileapi/File.h
@@ -32,6 +32,7 @@
 
 namespace WebCore {
 
+class ExceptionState;
 class ExecutionContext;
 struct FileMetadata;
 class KURL;
@@ -87,8 +88,8 @@ public:
     }
 
     virtual unsigned long long size() const OVERRIDE;
-    virtual PassRefPtr<Blob> slice(long long start = 0, long long end = std::numeric_limits<long long>::max(), const String& contentType = String()) const OVERRIDE;
-    virtual void close(ExecutionContext*) OVERRIDE;
+    virtual PassRefPtr<Blob> slice(long long start, long long end, const String& contentType, ExceptionState&) const OVERRIDE;
+    virtual void close(ExecutionContext*, ExceptionState&) OVERRIDE;
 
     virtual bool isFile() const OVERRIDE { return true; }
     virtual bool hasBackingFile() const OVERRIDE { return m_hasBackingFile; }