Expose WEBGL_debug_renderer_info through a chromium finch experiment.

Source/core/html/canvas/WebGLRenderingContext.h

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 521 matching lines @@
     RefPtr<WebGLCompressedTextureATC> m_webglCompressedTextureATC;
     RefPtr<WebGLCompressedTexturePVRTC> m_webglCompressedTexturePVRTC;
     RefPtr<WebGLCompressedTextureS3TC> m_webglCompressedTextureS3TC;
     RefPtr<WebGLDepthTexture> m_webglDepthTexture;
 
     enum ExtensionFlags {
         ApprovedExtension   = 0x00,
         DraftExtension      = 0x01,
         PrivilegedExtension = 0x02,
         PrefixedExtension   = 0x04,
+        WebGLDebugRendererInfoExtension = 0x08,
     };
 
     class ExtensionTracker {
     public:
         ExtensionTracker(ExtensionFlags flags, const char* const* prefixes)
             : m_privileged(flags & PrivilegedExtension)
             , m_draft(flags & DraftExtension)
             , m_prefixed(flags & PrefixedExtension)
+            , m_webglDebugRendererInfo(flags & WebGLDebugRendererInfoExtension)
             , m_prefixes(prefixes)
         {
         }
 
         virtual ~ExtensionTracker()
         {
         }
 
         bool prefixed() const
         {
             return m_prefixed;
         }
 
         bool privileged() const
         {
             return m_privileged;
         }
 
         bool draft() const
         {
             return m_draft;
         }
 
+        bool webglDebugRendererInfo() const
+        {
+            return m_webglDebugRendererInfo;
+        }
+
         bool matchesNameWithPrefixes(const String&) const;
 
         virtual PassRefPtr<WebGLExtension> getExtension(WebGLRenderingContext*) const = 0;
         virtual bool supported(WebGLRenderingContext*) const = 0;
         virtual const char* extensionName() const = 0;
         virtual void loseExtension() = 0;
 
     private:
         bool m_privileged;
         bool m_draft;
         bool m_prefixed;
+        bool m_webglDebugRendererInfo;
         const char* const* m_prefixes;
     };
 
     template <typename T>
     class TypedExtensionTracker : public ExtensionTracker {
     public:
         TypedExtensionTracker(RefPtr<T>& extensionField, ExtensionFlags flags, const char* const* prefixes)
             : ExtensionTracker(flags, prefixes)
             , m_extensionField(extensionField)
         {
@@ skipping 259 matching lines @@
     bool checkObjectToBeBound(const char* functionName, WebGLObject*, bool& deleted);
 
     void dispatchContextLostEvent(Timer<WebGLRenderingContext>*);
     // Helper for restoration after context lost.
     void maybeRestoreContext(Timer<WebGLRenderingContext>*);
 
     // Determine if we are running privileged code in the browser, for example,
     // a Safari or Chrome extension.
     bool allowPrivilegedExtensions() const;
 
+    // Determine if WEBGL_debug_renderer_info extension is enabled. For the
+    // moment it can be enabled either through a chromium finch experiment
+    // or for privileged code in the browser.
+    bool allowWebGLDebugRendererInfo() const;
+
     enum ConsoleDisplayPreference {
         DisplayInConsole,
         DontDisplayInConsole
     };
 
     // Wrapper for GraphicsContext3D::synthesizeGLError that sends a message
     // to the JavaScript console.
     void synthesizeGLError(GC3Denum, const char* functionName, const char* description, ConsoleDisplayPreference = DisplayInConsole);
     void emitGLWarning(const char* function, const char* reason);
 
@@ skipping 36 matching lines @@
     static void forciblyLoseOldestContext(const String& reason);
     // Return the least recently used context's position in the active context vector.
     // If the vector is empty, return the maximum allowed active context number.
     static size_t oldestContextIndex();
     static IntSize oldestContextSize();
 };
 
 } // namespace WebCore
 
 #endif