Limit the number of WebGL contexts that are active at any given time

Source/core/html/canvas/WebGLRenderingContext.h

Index: Source/core/html/canvas/WebGLRenderingContext.h
diff --git a/Source/core/html/canvas/WebGLRenderingContext.h b/Source/core/html/canvas/WebGLRenderingContext.h
index b10a174bebe6732e40c43f426d7b5e1aa69e1993..289d61e5f6975922010654b610dd7aa0b2be3b56 100644
--- a/Source/core/html/canvas/WebGLRenderingContext.h
+++ b/Source/core/html/canvas/WebGLRenderingContext.h
@@ -773,6 +773,16 @@ public:
     bool supportsDrawBuffers();
 
     friend class WebGLStateRestorer;
+    friend class WebGLRenderingContextEvictionManager;
+
+    static Vector<WebGLRenderingContext*>& activeContexts();
+    static Vector<WebGLRenderingContext*>& forciblyEvictedContexts();
+
+    static void activateContext(WebGLRenderingContext*);
+    static void deactivateContext(WebGLRenderingContext*, bool addToInactiveList);
+    static void willDestroyContext(WebGLRenderingContext*);
+    static void forciblyLoseOldestContext(const String& reason);
+    static IntSize oldestContextSize();
 };
 
 } // namespace WebCore