[webcrypto] Allow both ArrayBuffer and ArrayBufferView as inputs to crypto.subtle methods.

Source/wtf/ArrayPiece.cpp

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "wtf/ArrayPiece.h"
+
+#include "wtf/ArrayBuffer.h"
+#include "wtf/ArrayBufferView.h"
+#include "wtf/Assertions.h"
+
+namespace WTF {
+
+ArrayPiece::ArrayPiece()
+{
+    initNull();
+}
+
+ArrayPiece::ArrayPiece(void* data, unsigned byteLength)
+{
+    initWithData(data, byteLength);
+}
+
+ArrayPiece::ArrayPiece(ArrayBuffer* buffer)
+{
+    if (buffer) {
+        initWithData(buffer->data(), buffer->byteLength());
+    } else {
+        initNull();
+    }
+}
+
+ArrayPiece::ArrayPiece(ArrayBufferView* buffer)
+{
+    if (buffer) {
+        initWithData(buffer->baseAddress(), buffer->byteLength());
+    } else {
+        initNull();
+    }
+}
+
+bool ArrayPiece::isNull() const
+{
+    return m_isNull;
+}
+
+void* ArrayPiece::data() const
+{
+    ASSERT(!isNull());
+    return m_data;
+}
+
+unsigned char* ArrayPiece::bytes() const
+{
+    return static_cast<unsigned char*>(data());
+}
+
+unsigned ArrayPiece::byteLength() const
+{
+    ASSERT(!isNull());
+    return m_byteLength;
+}
+
+void ArrayPiece::initWithData(void* data, unsigned byteLength)
+{
+    m_byteLength = byteLength;
+    m_data = data;
+    m_isNull = false;
+}
+
+void ArrayPiece::initNull()
+{
+    m_byteLength = 0;
+    m_data = 0;
+    m_isNull = true;
+}
+
+} // namespace WTF