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;

[grt (UTC plus 2), 2015/09/05 12:44:14]

is this worth it for only one location? if you prefer it anyway, how about
moving it into the function so it's in the smallest scope possible?

[robertshield, 2015/09/13 06:04:02]

Done.

+
+// The registry path where the TriggeredReset values get set. Note that this
+// uses the same path for both SxS (Canary) and non-SxS Chrome.
+const wchar_t kTriggeredResetRegistryPath[] =
+    L"Software\\" PRODUCT_STRING_PATH L"\\TriggeredReset";
+
+const wchar_t kTriggeredResetToolName[] = L"ToolName";
+const wchar_t kTriggeredResetTimestamp[] = L"Timestamp";
+
+void TriggeredProfileResetter::Activate() {
+#if DCHECK_IS_ON()
+  activate_called_ = true;
+#endif
+
+  // 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())
+    return;
+
+  int64 timestamp = 0;
+  if (reset_reg_key.ReadInt64(kTriggeredResetTimestamp, &timestamp) !=
+      ERROR_SUCCESS) {
+    return;
+  }
+
+  // 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) {
+    DVLOG(1) << "Profile reset detected.";
+    has_reset_trigger_ = true;
+
+    if (reset_reg_key.ReadValue(kTriggeredResetToolName, &tool_name_) !=
+        ERROR_SUCCESS) {
+      DVLOG(1) << "Failed to read triggered profile reset tool name.";
+    } else if (tool_name_.length() > kMaxToolNameLength) {
+      tool_name_.resize(kMaxToolNameLength);
+    }
+
+    pref_service->SetInt64(prefs::kLastProfileResetTimestamp, timestamp);
+  }
+}