Add missing FileReader argument typechecking.

Source/core/fileapi/FileReader.cpp

 /*
  * Copyright (C) 2010 Google Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 142 matching lines @@
 
 void FileReader::stop()
 {
     if (m_loadingState == LoadingStateLoading || m_loadingState == LoadingStatePending)
         throttlingController()->removeReader(this);
     terminate();
 }
 
 void FileReader::readAsArrayBuffer(Blob* blob, ExceptionState& exceptionState)
 {
-    if (!blob)
+    if (!blob) {
+        exceptionState.throwTypeError("The argument is not a Blob.");
         return;
+    }
 
     WTF_LOG(FileAPI, "FileReader: reading as array buffer: %s %s\n", utf8BlobUUID(blob).data(), utf8FilePath(blob).data());
 
     readInternal(blob, FileReaderLoader::ReadAsArrayBuffer, exceptionState);
 }
 
 void FileReader::readAsBinaryString(Blob* blob, ExceptionState& exceptionState)
 {
-    if (!blob)
+    if (!blob) {
+        exceptionState.throwTypeError("The argument is not a Blob.");
         return;
+    }
 
     WTF_LOG(FileAPI, "FileReader: reading as binary: %s %s\n", utf8BlobUUID(blob).data(), utf8FilePath(blob).data());
 
     readInternal(blob, FileReaderLoader::ReadAsBinaryString, exceptionState);
 }
 
 void FileReader::readAsText(Blob* blob, const String& encoding, ExceptionState& exceptionState)
 {
-    if (!blob)
+    if (!blob) {
+        exceptionState.throwTypeError("The argument is not a Blob.");
         return;
+    }
 
     WTF_LOG(FileAPI, "FileReader: reading as text: %s %s\n", utf8BlobUUID(blob).data(), utf8FilePath(blob).data());
 
     m_encoding = encoding;
     readInternal(blob, FileReaderLoader::ReadAsText, exceptionState);
 }
 
 void FileReader::readAsText(Blob* blob, ExceptionState& exceptionState)
 {
     readAsText(blob, String(), exceptionState);
 }
 
 void FileReader::readAsDataURL(Blob* blob, ExceptionState& exceptionState)
 {
-    if (!blob)
+    if (!blob) {
+        exceptionState.throwTypeError("The argument is not a Blob.");
         return;
+    }
 
     WTF_LOG(FileAPI, "FileReader: reading as data URL: %s %s\n", utf8BlobUUID(blob).data(), utf8FilePath(blob).data());
 
     readInternal(blob, FileReaderLoader::ReadAsDataURL, exceptionState);
 }
 
 void FileReader::readInternal(Blob* blob, FileReaderLoader::ReadType type, ExceptionState& exceptionState)
 {
     // If multiple concurrent read methods are called on the same FileReader, InvalidStateError should be thrown when the state is LOADING.
     if (m_state == LOADING) {
-        exceptionState.throwUninformativeAndGenericDOMException(InvalidStateError);
+        exceptionState.throwDOMException(InvalidStateError, "The object is already busy reading Blobs.");
         return;
     }
 
     m_blob = blob;
     m_readType = type;
     m_state = LOADING;
     m_loadingState = LoadingStatePending;
     m_error = 0;
     throttlingController()->pushReader(this);
 }
@@ skipping 140 matching lines @@
 }
 
 String FileReader::stringResult()
 {
     if (!m_loader || m_error)
         return String();
     return m_loader->stringResult();
 }
 
 } // namespace WebCore