Fix DCHECK failure in extension_updater when scheduling first check

chrome/browser/extensions/updater/extension_updater.cc

Index: chrome/browser/extensions/updater/extension_updater.cc
diff --git a/chrome/browser/extensions/updater/extension_updater.cc b/chrome/browser/extensions/updater/extension_updater.cc
index 16e57c6690b0a298b2a46dac283c2075bfc960d1..7c27452192f94d4e91e49bb73db83a5a36847993 100644
--- a/chrome/browser/extensions/updater/extension_updater.cc
+++ b/chrome/browser/extensions/updater/extension_updater.cc
@@ -178,15 +178,14 @@ TimeDelta ExtensionUpdater::DetermineFirstCheckDelay() {
     return TimeDelta::FromSeconds(
         RandInt(kStartupWaitSeconds, frequency_seconds_));
 
+  // Read the persisted next check time, and use that if it isn't in the past
+  // or too far in the future (this can happen with system clock changes).
   Time saved_next = Time::FromInternalValue(prefs_->GetInt64(
       pref_names::kNextUpdateCheck));
-
   Time now = Time::Now();
-
-  // Read the persisted next check time, and use that if it isn't in the past
-  // or too far in the future (this can happen with system clock changes).
-  if (saved_next > now &&
-      saved_next < now + TimeDelta::FromSeconds(frequency_seconds_)) {
+  base::Time earliest = now + TimeDelta::FromSeconds(1);

[lazyboy, 2016/12/10 00:10:15]

The value 1 is coming from  ExtensionUpdater::ScheduleNextCheck, right? I'd put
this in a constant in this file's anonymous namspace.

Also add a dcheck in the constructor to ensure frequence_seconds_ is greater
than this. It already checks for >= 5, but that value can change independently.

[asargent_no_longer_on_chrome, 2016/12/14 23:01:19]

Done.

+  base::Time latest = now + TimeDelta::FromSeconds(frequency_seconds_);
+  if (saved_next > earliest && saved_next < latest) {
     return saved_next - now;
   }