Add a private API method to install a webstore app from Files.app

chrome/browser/chromeos/extensions/file_manager/private_api_misc.h

Index: chrome/browser/chromeos/extensions/file_manager/private_api_misc.h
diff --git a/chrome/browser/chromeos/extensions/file_manager/private_api_misc.h b/chrome/browser/chromeos/extensions/file_manager/private_api_misc.h
index 922864d2245fdd4506c684c6e1a45e7cbcf7e9ad..8eedc159fa779a69e815524c44e6a0fbf5ee54e3 100644
--- a/chrome/browser/chromeos/extensions/file_manager/private_api_misc.h
+++ b/chrome/browser/chromeos/extensions/file_manager/private_api_misc.h
@@ -97,6 +97,23 @@ class ZoomFunction : public SyncExtensionFunction {
   virtual bool RunImpl() OVERRIDE;
 };
 
+// Implements the chrome.fileBrowserPrivate.installWebstoreApp method.
+class InstallWebstoreAppFunction : public LoggedAsyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("fileBrowserPrivate.installWebstoreApp",
+                             FILEBROWSERPRIVATE_INSTALLWEBSTOREAPP);
+
+  InstallWebstoreAppFunction();
+
+ protected:
+  virtual ~InstallWebstoreAppFunction();
+  virtual bool RunImpl() OVERRIDE;
+  void OnInstallComplete(bool success, const std::string& error);
+
+ private:
+  std::string webstore_item_id_;
+};
+
 }  // namespace file_manager
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_MISC_H_