Put extension enable logic into a ExtensionEnableFlow.

chrome/browser/ui/extensions/extension_enable_flow.h

+// Copyright (c) 2012 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_UI_EXTENSIONS_EXTENSION_ENABLE_FLOW_H_
+#define CHROME_BROWSER_UI_EXTENSIONS_EXTENSION_ENABLE_FLOW_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/extensions/extension_install_prompt.h"
+
+class ExtensionEnableFlowDelegate;
+
+// ExtensionEnableFlow performs an UI flow to enable a disabled/terminated
+// extension. It calls its delegate when enabling is done or is aborted.
+// Callback on the delegate might be called synchronously if there is no
+// permission change while the extension is disabled/terminated (or the
+// extension is enabled already). Otherwise, a re-enable install prompt is
+// shown to user. The extension is enabled when user acknowledges it or the
+// flow is aborted when user declines it.
+class ExtensionEnableFlow : public ExtensionInstallPrompt::Delegate {
+ public:
+  ExtensionEnableFlow(Profile* profile,
+                      const std::string& extension_id,
+                      ExtensionEnableFlowDelegate* delegate);
+  virtual ~ExtensionEnableFlow();
+
+  // Starts the flow and the logic continues on |delegate_| after enabling is
+  // finished or aborted.
+  void Start();
+
+  const std::string& extension_id() const { return extension_id_; }
+
+ private:
+  // ExtensionInstallPrompt::Delegate overrides:
+  virtual void InstallUIProceed() OVERRIDE;
+  virtual void InstallUIAbort(bool user_initiated) OVERRIDE;
+
+  Profile* const profile_;
+  const std::string extension_id_;
+  ExtensionEnableFlowDelegate* const delegate_;  // Not owned.
+
+  scoped_ptr<ExtensionInstallPrompt> prompt_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionEnableFlow);
+};
+
+#endif  // CHROME_BROWSER_UI_EXTENSIONS_EXTENSION_ENABLE_FLOW_H_