Make callers of FromUTC(Local)Exploded in components/ use new time API.

components/autofill/content/browser/risk/fingerprint.cc

 // Copyright 2013 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.
 //
 // Generating a fingerprint consists of two major steps:
 //   (1) Gather all the necessary data.
 //   (2) Write it into a protocol buffer.
 //
 // Step (2) is as simple as it sounds -- it's really just a matter of copying
 // data.  Step (1) requires waiting on several asynchronous callbacks, which are
@@ skipping 47 matching lines @@
 // Maximum amount of time, in seconds, to wait for loading asynchronous
 // fingerprint data.
 const int kTimeoutSeconds = 4;
 
 // Returns the delta between the local timezone and UTC.
 base::TimeDelta GetTimezoneOffset() {
   const base::Time utc = base::Time::Now();
 
   base::Time::Exploded local;
   utc.LocalExplode(&local);
-
-  return base::Time::FromUTCExploded(local) - utc;
+  base::Time out_time;
+  // |out_time| is set to Time(0) on failure.
+  if (!base::Time::FromUTCExploded(local, &out_time)) {

[vabr (Chromium), 2016/06/28 14:34:12]

Given that the exploded value comes from the result of base::Time::Now(), how
could FromUTCExploded fail on it? It seems to me that a DCHECK is in order here:

bool conversion_success = base::Time::FromUTCExploded(local, &out_time);
DCHECK(conversion_success);

Please note that for reasons explained in my other comment, the conversion must
not be placed inside the DCHECK, and the DCHECK failure must not be handled.

[maksims (do not use this acc), 2016/06/29 05:48:59]

Correct, it will never fail in this case.

+    // TODO(maksims): implement error handling.
+    // |out_time| is Time(0) here.
+    NOTIMPLEMENTED();
+  }
+  return out_time - utc;
 }
 
 // Returns the concatenation of the operating system name and version, e.g.
 // "Mac OS X 10.6.8".
 std::string GetOperatingSystemVersion() {
   return base::SysInfo::OperatingSystemName() + " " +
       base::SysInfo::OperatingSystemVersion();
 }
 
 // Adds the list of |fonts| to the |machine|.
@@ skipping 393 matching lines @@
     host_view->GetRenderWidgetHost()->GetWebScreenInfo(&screen_info);
 
   internal::GetFingerprintInternal(
       obfuscated_gaia_id, window_bounds, content_bounds, screen_info, version,
       charset, accept_languages, install_time, app_locale, user_agent,
       base::TimeDelta::FromSeconds(kTimeoutSeconds), callback);
 }
 
 }  // namespace risk
 }  // namespace autofill