Add a triggered profile reset mechanism.

chrome/browser/profile_resetter/triggered_profile_resetter.h

Index: chrome/browser/profile_resetter/triggered_profile_resetter.h
diff --git a/chrome/browser/profile_resetter/triggered_profile_resetter.h b/chrome/browser/profile_resetter/triggered_profile_resetter.h
new file mode 100644
index 0000000000000000000000000000000000000000..1434b41219746a4d5c6eee1db9827c119819ded3
--- /dev/null
+++ b/chrome/browser/profile_resetter/triggered_profile_resetter.h
@@ -0,0 +1,75 @@
+// 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_PROFILE_RESETTER_TRIGGERED_PROFILE_RESETTER_H_
+#define CHROME_BROWSER_PROFILE_RESETTER_TRIGGERED_PROFILE_RESETTER_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/strings/string16.h"
+#include "components/keyed_service/core/keyed_service.h"
+
+class Profile;
+
+// This service is responsible for evaluating whether a profile reset trigger
+// has been set and not yet consumed by |profile_|. If it has, the profile is
+// eligible for reset and a profile reset UI will be show to the user. The
+// intended use case for this is to provide a sanctioned profile reset API for
+// third party tools (AVs or cleaner tools) that wish to reset user's profiles

[grt (UTC plus 2), 2015/09/04 18:35:48]

please choose one:
plural possessive: "reset users' profiles"
or singular: "reset a user's profiles"

[robertshield, 2015/09/04 20:27:18]

verily!

+// as part of their cleanup flow.
+//
+// To use this mechanism from a third party tool, perform the following steps:
+//   1) Create (or open) the registry key
+//      HCKU\Software\$PRODUCT_STRING_PATH\TriggeredReset where
+//      $PRODUCT_NAME is one of the values in chrome\common\chrome_constants.h,
+//      currently either "Google\\Chrome" or "Chromium"
+//   2) Set a REG_SZ value called "ToolName" to the name of the tool. This

[grt (UTC plus 2), 2015/09/04 18:35:48]

"to the localized name of the tool"?

[robertshield, 2015/09/04 20:27:18]

Done.

+//      string (truncated to kMaxToolNameLength) will be displayed in a
+//      notification UI.
+//   3) Set a REG_QWORD value with the timestamp of the reset. This value should
+//      be obtained from a call to ::GetSystemTimeAsFileTime(). This value
+//      will be persisted in a reset profile and will be used to avoid
+//      multiple resets.
+//
+// Some considerations:
+//
+// * Chrome supports multiple profiles. When the above steps are followed,
+//   each profile will enter the reset flow as it is opened.
+// * New profiles created while a timestamp is present will not get the reset
+//   flow.
+class TriggeredProfileResetter : public KeyedService {
+ public:
+  static const int kMaxToolNameLength = 100;

[grt (UTC plus 2), 2015/09/04 18:35:48]

  enum : int { MAX_TOOL_NAME_LENGTH = 100 };

(https://groups.google.com/a/chromium.org/d/msg/chromium-dev/hDqJ4KBVqog/jfNPH...)

[robertshield, 2015/09/04 20:27:18]

That thread was fun!

+
+  explicit TriggeredProfileResetter(Profile* profile);
+  ~TriggeredProfileResetter() override;
+
+  // Causes the TriggeredProfileResetter to look for the presence of a trigger
+  // and perform a reset, subsequent calls to HasResetTrigger will return
+  // whether |profile_| is subject to a reset.
+  virtual void Activate();
+
+  // Returns true iff the given profile should have a reset reset according to
+  // the description in the class comment. Must call Activate() first.
+  virtual bool HasResetTrigger();
+
+  // Returns the name of the tool that performed the reset. This string will be
+  // truncated to a length of |kMaxToolNameLength|.
+  virtual base::string16 GetResetToolName();
+
+ private:
+  Profile* profile_;
+
+  bool has_reset_trigger_ = false;
+  bool activate_called_ = false;

[grt (UTC plus 2), 2015/09/04 18:35:48]

#if DCHECK_IS_ON() around this?

[robertshield, 2015/09/04 20:27:18]

Done.

+
+  base::string16 tool_name_;
+
+  DISALLOW_COPY_AND_ASSIGN(TriggeredProfileResetter);
+};
+
+#endif  // CHROME_BROWSER_PROFILE_RESETTER_TRIGGERED_PROFILE_RESETTER_H_