Add a triggered profile reset mechanism.

chrome/browser/profile_resetter/triggered_profile_resetter_win.cc

+// 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.
+
+#include "chrome/browser/profile_resetter/triggered_profile_resetter.h"
+
+#include "base/prefs/pref_service.h"
+#include "base/win/registry.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/chrome_constants.h"
+#include "chrome/common/pref_names.h"
+
+using base::win::RegKey;
+
+const wchar_t kTriggeredResetRegistryPath[] =

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

please add a comment explaining that this location is used by both regular and
SxS Chrome.

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

Done.

+    L"Software\\" PRODUCT_STRING_PATH L"\\TriggeredReset";
+const wchar_t kTriggeredResetToolName[] = L"ToolName";
+const wchar_t kTriggeredResetTimestamp[] = L"Timestamp";
+
+void TriggeredProfileResetter::Activate() {
+  activate_called_ = true;

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

#if DCHECK_IS_ON() around this?

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

Done.

+
+  // System profiles don't contain user settings.
+  if (!profile_ || profile_->IsSystemProfile())
+    return;
+
+  RegKey reset_reg_key(HKEY_CURRENT_USER, kTriggeredResetRegistryPath,
+                       KEY_QUERY_VALUE | KEY_SET_VALUE);
+  if (reset_reg_key.Valid()) {

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

nit: reduce indentation with
  if (!Valid())
    return;

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

Done.

+    int64 timestamp = 0;
+    if (reset_reg_key.ReadInt64(kTriggeredResetTimestamp, &timestamp) ==

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

similar nit to early-exit and reduce indentation

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

Must be channeling my secret inner lisp programmer.

+        ERROR_SUCCESS) {
+      // A reset trigger time was found. Compare it to the trigger time stored
+      // in this profile. If different, reset the profile and persist the new
+      // time.
+      PrefService* pref_service = profile_->GetPrefs();
+      const int64 preference_timestamp =
+          pref_service->GetInt64(prefs::kLastProfileResetTimestamp);
+
+      if (profile_->IsNewProfile()) {
+        // New profiles should never be reset. Instead, persist the time stamp
+        // directly.
+        pref_service->SetInt64(prefs::kLastProfileResetTimestamp, timestamp);
+      } else if (timestamp != preference_timestamp) {
+        VLOG(1) << "Profile reset detected.";

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

DVLOG or remove

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

Done.

+        has_reset_trigger_ = true;
+
+        if (reset_reg_key.ReadValue(kTriggeredResetToolName, &tool_name_) !=
+            ERROR_SUCCESS) {
+          VLOG(1) << "Failed to read triggered profile reset tool name.";
+        }

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

} else if (tool_name_.length() > kMaxToolNameLength) {?

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

Done.

+        if (tool_name_.length() > kMaxToolNameLength)
+          tool_name_.resize(kMaxToolNameLength);
+
+        pref_service->SetInt64(prefs::kLastProfileResetTimestamp, timestamp);
+      }
+    }
+  }
+}