Remove dead DataView IDL and C++ code

Source/core/dom/DataView.idl

 /*
  * 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 11 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 // https://www.khronos.org/registry/typedarray/specs/latest/#DATAVIEW
 
 [
     ImplementedAs=DOMDataView,
     TypeChecking=Interface,
 ] interface DataView : ArrayBufferView {
-    // All these methods raise an exception if they would read or write beyond the end of the view.
-
-    [RaisesException] byte getInt8(unsigned long byteOffset);
-    [RaisesException] octet getUint8(unsigned long byteOffset);
-
-    [RaisesException] short getInt16(unsigned long byteOffset, optional boolean littleEndian);
-    [RaisesException] unsigned short getUint16(unsigned long byteOffset, optional boolean littleEndian);
-    [RaisesException] long getInt32(unsigned long byteOffset, optional boolean littleEndian);
-    [RaisesException] unsigned long getUint32(unsigned long byteOffset, optional boolean littleEndian);
-
-    [RaisesException] float getFloat32(unsigned long byteOffset, optional boolean littleEndian);
-    [RaisesException] double getFloat64(unsigned long byteOffset, optional boolean littleEndian);
-
-    [RaisesException] void setInt8(unsigned long byteOffset, byte value);
-    [RaisesException] void setUint8(unsigned long byteOffset, octet value);
-
-    [RaisesException] void setInt16(unsigned long byteOffset, short value, optional boolean littleEndian);
-    [RaisesException] void setUint16(unsigned long byteOffset, unsigned short value, optional boolean littleEndian);
-    [RaisesException] void setInt32(unsigned long byteOffset, long value, optional boolean littleEndian);
-    [RaisesException] void setUint32(unsigned long byteOffset, unsigned long value, optional boolean littleEndian);
-    [RaisesException] void setFloat32(unsigned long byteOffset, unrestricted float value, optional boolean littleEndian);
-    [RaisesException] void setFloat64(unsigned long byteOffset, unrestricted double value, optional boolean littleEndian);
 };