Completely removed the Extensions3D class (Take 2)

Source/core/html/canvas/WebGLCompressedTexturePVRTC.cpp

Index: Source/core/html/canvas/WebGLCompressedTexturePVRTC.cpp
diff --git a/Source/core/html/canvas/WebGLCompressedTexturePVRTC.cpp b/Source/core/html/canvas/WebGLCompressedTexturePVRTC.cpp
index 8ae4acd26899e81a50385d44943c1ebbcca29b6d..4c720aeb32b047ba8eedda09f2a2768954d4ab52 100644
--- a/Source/core/html/canvas/WebGLCompressedTexturePVRTC.cpp
+++ b/Source/core/html/canvas/WebGLCompressedTexturePVRTC.cpp
@@ -28,7 +28,6 @@
 #include "core/html/canvas/WebGLCompressedTexturePVRTC.h"
 
 #include "core/html/canvas/WebGLRenderingContext.h"
-#include "platform/graphics/Extensions3D.h"
 
 namespace WebCore {
 
@@ -36,10 +35,10 @@ WebGLCompressedTexturePVRTC::WebGLCompressedTexturePVRTC(WebGLRenderingContext*
     : WebGLExtension(context)
 {
     ScriptWrappable::init(this);
-    context->addCompressedTextureFormat(Extensions3D::COMPRESSED_RGB_PVRTC_4BPPV1_IMG);
-    context->addCompressedTextureFormat(Extensions3D::COMPRESSED_RGB_PVRTC_2BPPV1_IMG);
-    context->addCompressedTextureFormat(Extensions3D::COMPRESSED_RGBA_PVRTC_4BPPV1_IMG);
-    context->addCompressedTextureFormat(Extensions3D::COMPRESSED_RGBA_PVRTC_2BPPV1_IMG);
+    context->addCompressedTextureFormat(GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG);
+    context->addCompressedTextureFormat(GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG);
+    context->addCompressedTextureFormat(GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG);
+    context->addCompressedTextureFormat(GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG);
 }
 
 WebGLCompressedTexturePVRTC::~WebGLCompressedTexturePVRTC()
@@ -58,8 +57,7 @@ PassRefPtr<WebGLCompressedTexturePVRTC> WebGLCompressedTexturePVRTC::create(WebG
 
 bool WebGLCompressedTexturePVRTC::supported(WebGLRenderingContext* context)
 {
-    Extensions3D* extensions = context->graphicsContext3D()->extensions();
-    return extensions->supports("GL_IMG_texture_compression_pvrtc");
+    return context->graphicsContext3D()->supportsExtension("GL_IMG_texture_compression_pvrtc");
 }
 
 const char* WebGLCompressedTexturePVRTC::extensionName()