Create MetricsPrivateDelegate for metricsPrivate behavior

extensions/shell/browser/shell_extensions_api_client.h

Index: extensions/shell/browser/shell_extensions_api_client.h
diff --git a/extensions/shell/browser/shell_extensions_api_client.h b/extensions/shell/browser/shell_extensions_api_client.h
index 17a26fc78c1c7bbd2e92a844cd5b63637b938ebc..568b31e4d64704c1bfc1428a7afdefe1ca90e3c7 100644
--- a/extensions/shell/browser/shell_extensions_api_client.h
+++ b/extensions/shell/browser/shell_extensions_api_client.h
@@ -5,18 +5,29 @@
 #ifndef EXTENSIONS_SHELL_BROWSER_SHELL_EXTENSIONS_API_CLIENT_H_
 #define EXTENSIONS_SHELL_BROWSER_SHELL_EXTENSIONS_API_CLIENT_H_
 
+#include <memory>
+
 #include "extensions/browser/api/extensions_api_client.h"
 
 namespace extensions {
 
+class ShellMetricsPrivateDelegate;
+
 class ShellExtensionsAPIClient : public ExtensionsAPIClient {
  public:
   ShellExtensionsAPIClient();
+  ~ShellExtensionsAPIClient() override;
 
   // ExtensionsAPIClient implementation.
   void AttachWebContentsHelpers(content::WebContents* web_contents) const
       override;
   AppViewGuestDelegate* CreateAppViewGuestDelegate() const override;
+  MetricsPrivateDelegate* GetMetricsPrivateDelegate() override;
+
+ private:
+  std::unique_ptr<ShellMetricsPrivateDelegate> metrics_private_delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShellExtensionsAPIClient);
 };
 
 }  // namespace extensions