Rename ViewportObserver to SkyEngine

sky/shell/testing/test_runner.h

Index: sky/shell/testing/test_runner.h
diff --git a/sky/shell/testing/test_runner.h b/sky/shell/testing/test_runner.h
index eb27c13d6ebe5ff5da62c8f78c1e9043d0622fd5..7b326abd554ab7cdc47c6b7df4e7eda7eab18c55 100644
--- a/sky/shell/testing/test_runner.h
+++ b/sky/shell/testing/test_runner.h
@@ -11,8 +11,8 @@
 #include "base/memory/weak_ptr.h"
 #include "mojo/common/weak_binding_set.h"
 #include "mojo/public/cpp/application/interface_factory_impl.h"
+#include "sky/services/engine/sky_engine.mojom.h"
 #include "sky/services/testing/test_harness.mojom.h"
-#include "sky/services/viewport/viewport_observer.mojom.h"
 
 namespace sky {
 namespace shell {
@@ -46,7 +46,7 @@ class TestRunner : public mojo::InterfaceFactory<TestHarness>,
 
   std::string package_root_;
   scoped_ptr<ShellView> shell_view_;
-  ViewportObserverPtr viewport_observer_;
+  SkyEnginePtr sky_engine_;
 
   std::string single_test_url_;
   mojo::WeakBindingSet<TestHarness> bindings_;