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 a52eb64d68173acf513ef3209fef55b7db695da7..2017d0cf678be9a6c5bc83c92fb651aa53b8ad2b 100644
--- a/Source/core/html/canvas/WebGLRenderingContextBase.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
@@ -831,6 +831,12 @@ void WebGLRenderingContextBase::markLayerComposited()
         m_drawingBuffer->markLayerComposited();
 }
 
+void WebGLRenderingContextBase::setIsHidden(bool hidden)
+{
+    if (!isContextLost())
+        m_drawingBuffer->setIsHidden(hidden);
+}
+
 void WebGLRenderingContextBase::paintRenderingResultsToCanvas()
 {
     if (isContextLost()) {