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

Source/core/html/canvas/WebGLRenderingContextBase.cpp

Index: Source/core/html/canvas/WebGLRenderingContextBase.cpp
diff --git a/Source/core/html/canvas/WebGLRenderingContextBase.cpp b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
index f6e130a8b0e8d6ea8f1459cfb7b965b6bfde7bb2..09b480a1855116145b27f9883986745654f729ba 100644
--- a/Source/core/html/canvas/WebGLRenderingContextBase.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
@@ -822,6 +822,12 @@ void WebGLRenderingContextBase::markLayerComposited()
         m_drawingBuffer->markLayerComposited();
 }
 
+void WebGLRenderingContextBase::setIsHidden(bool hidden)
+{
+    if (!isContextLost())
+        m_drawingBuffer->setIsHidden(hidden);
+}
+
 void WebGLRenderingContextBase::paintRenderingResultsToCanvas()
 {
     if (isContextLost()) {