Moved the majority of WebGL functionality into WebGLRenderingContextBase

Source/core/html/canvas/OESStandardDerivatives.cpp

Index: Source/core/html/canvas/OESStandardDerivatives.cpp
diff --git a/Source/core/html/canvas/OESStandardDerivatives.cpp b/Source/core/html/canvas/OESStandardDerivatives.cpp
index 442640c54d0c433ef5b885c71f364a10d411bde9..493063486d2fd7db1dd6ecd9d6051a1a14804354 100644
--- a/Source/core/html/canvas/OESStandardDerivatives.cpp
+++ b/Source/core/html/canvas/OESStandardDerivatives.cpp
@@ -30,7 +30,7 @@
 
 namespace WebCore {
 
-OESStandardDerivatives::OESStandardDerivatives(WebGLRenderingContext* context)
+OESStandardDerivatives::OESStandardDerivatives(WebGLRenderingContextBase* context)
     : WebGLExtension(context)
 {
     ScriptWrappable::init(this);
@@ -46,12 +46,12 @@ WebGLExtension::ExtensionName OESStandardDerivatives::getName() const
     return OESStandardDerivativesName;
 }
 
-PassRefPtr<OESStandardDerivatives> OESStandardDerivatives::create(WebGLRenderingContext* context)
+PassRefPtr<OESStandardDerivatives> OESStandardDerivatives::create(WebGLRenderingContextBase* context)
 {
     return adoptRef(new OESStandardDerivatives(context));
 }
 
-bool OESStandardDerivatives::supported(WebGLRenderingContext* context)
+bool OESStandardDerivatives::supported(WebGLRenderingContextBase* context)
 {
     Extensions3D* extensions = context->graphicsContext3D()->getExtensions();
     return extensions->supports("GL_OES_standard_derivatives");