Add mash shelf application id support.

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 cc77a7b1c7332a4021e59456b5903f45bd2d3c5c..87209697634b1e1a2b6ec6f72488a11fd66e2f54 100644
--- a/content/public/common/mojo_shell_connection.h
+++ b/content/public/common/mojo_shell_connection.h
@@ -9,6 +9,7 @@
 
 #include "base/callback_forward.h"
 #include "content/common/content_export.h"
+#include "services/shell/public/cpp/identity.h"
 #include "services/shell/public/interfaces/shell_client.mojom.h"
 
 namespace shell {
@@ -57,6 +58,8 @@ class CONTENT_EXPORT MojoShellConnection {
 
   virtual shell::Connector* GetConnector() = 0;
 
+  virtual const shell::Identity& GetIdentity() const = 0;
+
   // Indicates whether the shell connection is to an external shell (true) or
   // a shell embedded in the browser process (false).
   virtual bool UsingExternalShell() const = 0;