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 8fb31fa2206334a4892cae55288da7a9b2a5c53e..c87947d9b847d934409674417a61f967d076e3d5 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -2293,6 +2293,13 @@ int CanvasRenderingContext2D::getFontBaseline(const FontMetrics& fontMetrics) co
     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;