Remove unnecessary WebGLRenderingContextBase unregistration.

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
index 5ca7f02851af3d9a8950c6e5695d30daf779ca20..e8677e30f41e0d846753573a44882d51c8ae9a37 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
@@ -205,8 +205,15 @@ void WebGLRenderingContextBase::removeFromEvictedList(WebGLRenderingContextBase*
 
 void WebGLRenderingContextBase::willDestroyContext(WebGLRenderingContextBase* context)
 {
+#if ENABLE(OILPAN)
+    // These two sets keep weak references to their contexts;
+    // verify that the GC already removed the |context| entries.
+    ASSERT(!forciblyEvictedContexts().contains(context));
+    ASSERT(!activeContexts().contains(context));
+#else
     removeFromEvictedList(context);
     deactivateContext(context);
+#endif
 
     // Try to re-enable the oldest inactive contexts.
     while (activeContexts().size() < maxGLActiveContexts && forciblyEvictedContexts().size()) {