Make SkGLContext lifetime more well-defined

tests/EGLImageTest.cpp

Index: tests/EGLImageTest.cpp
diff --git a/tests/EGLImageTest.cpp b/tests/EGLImageTest.cpp
index b5754d8eb5ff130778096bc3a93cfc406196a31e..fdae3b32d1eb9e5e715c52833bf59a73a0c80888 100644
--- a/tests/EGLImageTest.cpp
+++ b/tests/EGLImageTest.cpp
@@ -28,7 +28,6 @@ static void cleanup(SkGLContext* glctx0, GrGLuint texID0, SkGLContext* glctx1, G
         if (GR_EGL_NO_IMAGE != image1) {
             glctx1->destroyEGLImage(image1);
         }
-        glctx1->unref();
     }
 
     glctx0->makeCurrent();
@@ -91,7 +90,7 @@ DEF_GPUTEST_FOR_RENDERING_CONTEXTS(EGLImageTest, reporter, context0, glCtx0) {
         return;
     }
 
-    SkGLContext* glCtx1 = glCtx0->createNew();
+    SkAutoTDelete<SkGLContext> glCtx1 = glCtx0->createNew();
     if (!glCtx1) {
         return;
     }