X-Chrome-Variations logic refactoring

chrome/browser/autocomplete/autocomplete_field_trial.cc

Index: chrome/browser/autocomplete/autocomplete_field_trial.cc
diff --git a/chrome/browser/autocomplete/autocomplete_field_trial.cc b/chrome/browser/autocomplete/autocomplete_field_trial.cc
index e7331c4a8ea80b733060745ad0f3bfe7a1ee228b..e7dd484744db7dd64bd2b1fc59afd93ab1fb8a8e 100644
--- a/chrome/browser/autocomplete/autocomplete_field_trial.cc
+++ b/chrome/browser/autocomplete/autocomplete_field_trial.cc
@@ -19,8 +19,8 @@ static const char kDisallowInlineHQPFieldTrialName[] =
 // Because we regularly change the name of the suggest field trial in
 // order to shuffle users among groups, we use the date the current trial
 // was created as part of the name.
-static const char kSuggestFieldTrialStarted2012Q4Name[] =
-    "OmniboxSearchSuggestTrialStarted2012Q4";
+static const char kSuggestFieldTrialStarted2013Q1Name[] =
+    "OmniboxSearchSuggestTrialStarted2013Q1";
 static const char kHQPNewScoringFieldTrialName[] =
     "OmniboxHQPNewScoringMax1400";
 static const char kHUPCullRedirectsFieldTrialName[] = "OmniboxHUPCullRedirects";
@@ -135,18 +135,18 @@ void AutocompleteFieldTrial::Activate() {
   // Create the suggest field trial.
   // Make it expire on July 1, 2013.
   trial = base::FieldTrialList::FactoryGetFieldTrial(
-      kSuggestFieldTrialStarted2012Q4Name, kSuggestFieldTrialNumberOfGroups,
+      kSuggestFieldTrialStarted2013Q1Name, kSuggestFieldTrialNumberOfGroups,
       "0", 2013, 7, 1, NULL);

[Mark P, 2012/12/14 16:56:41]

Let's bump the expiration date a bit too.  How about
7 -> 9

[Bart N., 2012/12/14 17:06:07]

Done.

[Mark P, 2012/12/14 17:09:55]

And the word July -> September.
(sorry I forgot to mention this)

[Bart N., 2012/12/14 18:21:42]

Yeah, I haven't noticed either :) Done.

On a side note, I think we should get rid of the comment (both lines). In
general, we should avoid comments that state obvious things. In this particular
case the comments don't bring anything that is not already clearly expressed in
the arguments below.

On the other hand, if the date year/mm/day was encoded as a number of days since
1900/1/1, it'd totally make sense to have the comment.

[Mark P, 2012/12/14 18:37:34]

I've seen bugs where the coder has the wrong order for dates (1/7 vs 7/1).  This
wasn't caught by the reviewer because the reviewer didn't know when the coder
intended things to expire so the dates looked fine to him.  So the explanation
at least helps the reviewer check the code.   Whether it needs to be there in a
comment in the file, that's another question...

in any case, this is fine as is.

[Bart N., 2012/12/14 18:52:33]

Coming from Europe, I've experienced this issues many times. In such cases, if
possible, a better approach is to pick date such as there is no confusion. In
this case, I'd simply change it to the last day of the previous month, e.g. 6/30
instead of 1/7. This approach is better, because most likely we will get a
DCHECK failure somewhere. A reviewer may still fail to notice the wrong format.

   trial->UseOneTimeRandomization();
 
   // Mark this group in suggest requests to Google.
   chrome_variations::AssociateGoogleVariationID(
       chrome_variations::GOOGLE_WEB_PROPERTIES,
-      kSuggestFieldTrialStarted2012Q4Name, "0",
-      chrome_variations::kSuggestTrialStarted2012Q4IDMin);
+      kSuggestFieldTrialStarted2013Q1Name, "0",
+      chrome_variations::kSuggestTrialStarted2013Q1IDMin);
   DCHECK_EQ(kSuggestFieldTrialNumberOfGroups,
-      chrome_variations::kSuggestTrialStarted2012Q4IDMax -
-      chrome_variations::kSuggestTrialStarted2012Q4IDMin + 1);
+      chrome_variations::kSuggestTrialStarted2013Q1IDMax -
+      chrome_variations::kSuggestTrialStarted2013Q1IDMin + 1);
 
   // We've already created one group; now just need to create
   // kSuggestFieldTrialNumGroups - 1 more. Mark these groups in
@@ -156,9 +156,9 @@ void AutocompleteFieldTrial::Activate() {
     trial->AppendGroup(group_name, 1);
     chrome_variations::AssociateGoogleVariationID(
         chrome_variations::GOOGLE_WEB_PROPERTIES,
-        kSuggestFieldTrialStarted2012Q4Name, group_name,
+        kSuggestFieldTrialStarted2013Q1Name, group_name,
         static_cast<chrome_variations::VariationID>(
-            chrome_variations::kSuggestTrialStarted2012Q4IDMin + i));
+            chrome_variations::kSuggestTrialStarted2013Q1IDMin + i));
   }
 
   // Make sure that we participate in the suggest experiment by calling group()