Make PlatformViewport and NativeViewportImpl use Shell* instead of ApplicationImpl*.

services/native_viewport/platform_viewport.h

Index: services/native_viewport/platform_viewport.h
diff --git a/services/native_viewport/platform_viewport.h b/services/native_viewport/platform_viewport.h
index 519265422afcf9536ea21199c6021f0b2392ea62..4d23c739991e4c19aa20548da2a243eafa41681f 100644
--- a/services/native_viewport/platform_viewport.h
+++ b/services/native_viewport/platform_viewport.h
@@ -16,7 +16,7 @@ class Rect;
 }
 
 namespace mojo {
-class ApplicationImpl;
+class Shell;
 }
 
 namespace native_viewport {
@@ -45,7 +45,9 @@ class PlatformViewport {
   virtual gfx::Size GetSize() = 0;
   virtual void SetBounds(const gfx::Rect& bounds) = 0;
 
-  static scoped_ptr<PlatformViewport> Create(mojo::ApplicationImpl* application,
+  // TODO(vtl): Maybe this should take an
+  // |InterfaceHandle<ApplicationConnector>| instead of a |Shell*|.
+  static scoped_ptr<PlatformViewport> Create(mojo::Shell* shell,
                                              Delegate* delegate);
 };