Extract shell methods from ApplicationImpl into a base class, and pass this to Initialize() instead.

content/public/common/mojo_shell_connection.h

Index: content/public/common/mojo_shell_connection.h
diff --git a/content/public/common/mojo_shell_connection.h b/content/public/common/mojo_shell_connection.h
index 62c9e3c442b3c8e2cce622f593e4f7ab1a670bd3..584073ce58c93ced8304d374a0efbfb207508b19 100644
--- a/content/public/common/mojo_shell_connection.h
+++ b/content/public/common/mojo_shell_connection.h
@@ -9,7 +9,7 @@
 
 namespace mojo {
 class ApplicationConnection;
-class ApplicationImpl;
+class Shell;
 }
 
 namespace content {
@@ -41,8 +41,8 @@ class CONTENT_EXPORT MojoShellConnection {
   // created on.
   static void Destroy();
 
-  // Returns an Initialized() ApplicationImpl.
-  virtual mojo::ApplicationImpl* GetApplication() = 0;
+  // Returns an Initialized() Shell.
+  virtual mojo::Shell* GetShell() = 0;
 
   // [De]Register an impl of Listener that will be consulted when the wrapped
   // ApplicationImpl exposes services to inbound connections.