Completely removed the Extensions3D class (Take 2)

Source/core/html/canvas/WebGLCompressedTextureATC.cpp

Index: Source/core/html/canvas/WebGLCompressedTextureATC.cpp
diff --git a/Source/core/html/canvas/WebGLCompressedTextureATC.cpp b/Source/core/html/canvas/WebGLCompressedTextureATC.cpp
index dad7ff49b059378b30c9eadaffb2c7bfe9662f9f..d5f6824ebc070e97836981aa38691a74439ab604 100644
--- a/Source/core/html/canvas/WebGLCompressedTextureATC.cpp
+++ b/Source/core/html/canvas/WebGLCompressedTextureATC.cpp
@@ -27,17 +27,15 @@
 
 #include "core/html/canvas/WebGLCompressedTextureATC.h"
 
-#include "platform/graphics/Extensions3D.h"
-
 namespace WebCore {
 
 WebGLCompressedTextureATC::WebGLCompressedTextureATC(WebGLRenderingContext* context)
     : WebGLExtension(context)
 {
     ScriptWrappable::init(this);
-    context->addCompressedTextureFormat(Extensions3D::COMPRESSED_ATC_RGB_AMD);
-    context->addCompressedTextureFormat(Extensions3D::COMPRESSED_ATC_RGBA_EXPLICIT_ALPHA_AMD);
-    context->addCompressedTextureFormat(Extensions3D::COMPRESSED_ATC_RGBA_INTERPOLATED_ALPHA_AMD);
+    context->addCompressedTextureFormat(GC3D_COMPRESSED_ATC_RGB_AMD);
+    context->addCompressedTextureFormat(GC3D_COMPRESSED_ATC_RGBA_EXPLICIT_ALPHA_AMD);
+    context->addCompressedTextureFormat(GC3D_COMPRESSED_ATC_RGBA_INTERPOLATED_ALPHA_AMD);
 }
 
 WebGLCompressedTextureATC::~WebGLCompressedTextureATC()
@@ -56,8 +54,7 @@ PassRefPtr<WebGLCompressedTextureATC> WebGLCompressedTextureATC::create(WebGLRen
 
 bool WebGLCompressedTextureATC::supported(WebGLRenderingContext* context)
 {
-    Extensions3D* extensions = context->graphicsContext3D()->extensions();
-    return extensions->supports("GL_AMD_compressed_ATC_texture");
+    return context->graphicsContext3D()->supportsExtension("GL_AMD_compressed_ATC_texture");
 }
 
 const char* WebGLCompressedTextureATC::extensionName()