Only show high efficiency chip at most once every N days

The time duration between showing the chip is configurable via
Finch which will allow us to do experimentation. The last instance
of the chip being expanded is a user pref.

Bug: 1424229
Change-Id: Ibe5628ef5edfedff013327b8c577c92625bbc36d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4456167
Reviewed-by: Dominic Battre <[email protected]>
Commit-Queue: Alison Gale <[email protected]>
Reviewed-by: Eshwar Stalin <[email protected]>
Code-Coverage: Findit <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1133817}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 08fc2ac..7db8872 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -1737,6 +1737,8 @@
 
 #if !BUILDFLAG(IS_ANDROID)
   registry->RegisterIntegerPref(prefs::kHighEfficiencyChipExpandedCount, 0);
+  registry->RegisterTimePref(prefs::kLastHighEfficiencyChipExpandedTimestamp,
+                             base::Time());
   permissions::PermissionHatsTriggerHelper::RegisterProfilePrefs(registry);
 #endif