Implement the chrome.passwordsPrivate API.

chrome/browser/extensions/api/passwords_private/passwords_private_api.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_PASSWORDS_PRIVATE_PASSWORDS_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_PASSWORDS_PRIVATE_PASSWORDS_PRIVATE_API_H_
 
 #include <string>
 
 #include "base/macros.h"
+#include "chrome/browser/extensions/api/passwords_private/passwords_private_delegate.h"
+#include "chrome/browser/ui/passwords/password_manager_presenter.h"
 #include "extensions/browser/extension_function.h"
 
 namespace extensions {
 
 class PasswordsPrivateCanPasswordAccountBeManagedFunction :
     public UIThreadExtensionFunction {
  public:
   PasswordsPrivateCanPasswordAccountBeManagedFunction() {}
   DECLARE_EXTENSION_FUNCTION("passwordsPrivate.canPasswordAccountBeManaged",
                              PASSWORDSPRIVATE_CANPASSWORDACCOUNTBEMANAGED);
@@ skipping 38 matching lines @@
   // ExtensionFunction overrides.
   ResponseAction Run() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PasswordsPrivateRemovePasswordExceptionFunction);
 };
 
 class PasswordsPrivateGetPlaintextPasswordFunction :
     public UIThreadExtensionFunction {
  public:
-  PasswordsPrivateGetPlaintextPasswordFunction() {}
-  DECLARE_EXTENSION_FUNCTION("passwordsPrivate.GetPlaintextPassword",
+  PasswordsPrivateGetPlaintextPasswordFunction();
+  DECLARE_EXTENSION_FUNCTION("passwordsPrivate.getPlaintextPassword",
                              PASSWORDSPRIVATE_GETPLAINTEXTPASSWORD);
 
  protected:
   ~PasswordsPrivateGetPlaintextPasswordFunction() override;
 
   // ExtensionFunction overrides.
   ResponseAction Run() override;
 
  private:
+  // Called by the observer when the password has been retrieved so that this
+  // function can return the password value.
+  void ReplyWithPlaintextPassword(const std::string& plaintext_password);
+
+  // Observer used by PasswordsPrivateGetPlaintextPasswordFunction to listen
+  // for when PasswordsPrivateDelegate fetches the requested plaintext
+  // password.
+  class PlaintextPasswordObserver :

[Ken Rockot(use gerrit already), 2015/05/22 16:42:28]

You can just declare the existence of the class here:

class PlaintextPasswordObserver;


and move the entire definition into the cc.

[Kyle Horimoto, 2015/05/22 17:52:53]

Done.

+      public extensions::PasswordsPrivateDelegate::Observer {
+   public:
+    PlaintextPasswordObserver(
+        const extensions::api::passwords_private::LoginPair& login_pair,
+        const scoped_refptr<extensions::
+            PasswordsPrivateGetPlaintextPasswordFunction> fn_needing_reply,
+        extensions::PasswordsPrivateDelegate* delegate);
+    ~PlaintextPasswordObserver() override;
+
+    // extensions::PasswordsPrivateDelegate::Observer overrides;
+    void OnPlaintextPasswordFetched(
+        const std::string& origin_url,
+        const std::string& username,
+        const std::string& password_value) override;
+
+   private:
+    // The LoginPair whose password is being requested.
+    extensions::api::passwords_private::LoginPair login_pair_;
+
+    // The function waiting on a response containing the password. A
+    // scoped_refptr is used to ensure that the function is not deleted before
+    // the plaintext password has been returned.
+    scoped_refptr<extensions::PasswordsPrivateGetPlaintextPasswordFunction>
+        fn_needing_reply_;
+
+    // The delegate this class is observing.
+    extensions::PasswordsPrivateDelegate* delegate_;
+  };
+
+  PlaintextPasswordObserver* observer_;
+
   DISALLOW_COPY_AND_ASSIGN(PasswordsPrivateGetPlaintextPasswordFunction);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_PASSWORDS_PRIVATE_PASSWORDS_PRIVATE_API_H_