Revert of WebGL: Free temporary GPU resources held by inactive or hidden WebGL.

Source/core/html/canvas/CanvasRenderingContext2D.cpp

Index: Source/core/html/canvas/CanvasRenderingContext2D.cpp
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.cpp b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
index 5e951e62ec00c761a257183c226b01adadd01e81..d71fa2918bff5ff9cda380ecc013c34614338c6e 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -2266,13 +2266,6 @@
     return 0;
 }
 
-void CanvasRenderingContext2D::setIsHidden(bool hidden)
-{
-    ImageBuffer* buffer = canvas()->buffer();
-    if (buffer)
-        buffer->setIsHidden(hidden);
-}
-
 blink::WebLayer* CanvasRenderingContext2D::platformLayer() const
 {
     return canvas()->buffer() ? canvas()->buffer()->platformLayer() : 0;