Added support for EXTDisjointTimerQuery on the Blink side.

Source/modules/webgl/EXTDisjointTimerQuery.h

Index: Source/modules/webgl/EXTDisjointTimerQuery.h
diff --git a/Source/modules/webgl/EXTDisjointTimerQuery.h b/Source/modules/webgl/EXTDisjointTimerQuery.h
new file mode 100644
index 0000000000000000000000000000000000000000..8a3931552f10a8684e2d7f187b61e5ba6f8df8f5
--- /dev/null
+++ b/Source/modules/webgl/EXTDisjointTimerQuery.h
@@ -0,0 +1,49 @@
+// Copyright 2015 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.
+
+#ifndef EXTDisjointTimerQuery_h
+#define EXTDisjointTimerQuery_h
+
+#include "bindings/core/v8/ScriptValue.h"
+#include "modules/webgl/WebGLExtension.h"
+#include "wtf/HashMap.h"
+
+namespace blink {
+
+class WebGLRenderingContextBase;
+class WebGLTimerQueryEXT;
+
+class EXTDisjointTimerQuery final : public WebGLExtension {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    static EXTDisjointTimerQuery* create(WebGLRenderingContextBase*);
+    static bool supported(WebGLRenderingContextBase*);
+    static const char* extensionName();
+
+    ~EXTDisjointTimerQuery() override;
+    WebGLExtensionName name() const override;
+
+    WebGLTimerQueryEXT* createQueryEXT();
+    void deleteQueryEXT(WebGLTimerQueryEXT*);
+    GLboolean isQueryEXT(WebGLTimerQueryEXT*);
+    void beginQueryEXT(GLenum, WebGLTimerQueryEXT*);
+    void endQueryEXT(GLenum);
+    void queryCounterEXT(WebGLTimerQueryEXT*, GLenum);
+    ScriptValue getQueryEXT(ScriptState*, GLenum, GLenum);
+    ScriptValue getQueryObjectEXT(ScriptState*, WebGLTimerQueryEXT*, GLenum);
+
+    DECLARE_VIRTUAL_TRACE();
+
+private:
+    friend class WebGLTimerQueryEXT;
+    explicit EXTDisjointTimerQuery(WebGLRenderingContextBase*);
+
+    void OnQueryDeleted(GLuint);
+
+    Member<WebGLTimerQueryEXT> m_currentElapsedQuery;
+};
+
+} // namespace blink
+
+#endif // EXTDisjointTimerQuery_h