Some cleanup of GrResource

Review URL: http://codereview.appspot.com/6139043/



git-svn-id: http://skia.googlecode.com/svn/trunk@3782 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrResource.cpp b/src/gpu/GrResource.cpp
index 63d2e7b..9efc838 100644
--- a/src/gpu/GrResource.cpp
+++ b/src/gpu/GrResource.cpp
@@ -17,6 +17,11 @@
     fGpu->insertResource(this);
 }
 
+GrResource::~GrResource() {
+    // subclass should have released this.
+    GrAssert(!this->isValid());
+}
+
 void GrResource::release() {
     if (NULL != fGpu) {
         this->onRelease();