Parametrize Suggest polling strategy and delay. Also add a parameter

components/omnibox/omnibox_field_trial.cc

Index: components/omnibox/omnibox_field_trial.cc
diff --git a/components/omnibox/omnibox_field_trial.cc b/components/omnibox/omnibox_field_trial.cc
index 96adb803263731c2b3bc50e7b913c7a362dee699..3f2cc07f5b0c4b66df2d4b92f7910ab17b7cfe2d 100644
--- a/components/omnibox/omnibox_field_trial.cc
+++ b/components/omnibox/omnibox_field_trial.cc
@@ -336,6 +336,29 @@ bool OmniboxFieldTrial::DisplayHintTextWhenPossible() {
       kDisplayHintTextWhenPossibleRule) == "true";
 }
 
+bool OmniboxFieldTrial::DisableResultsCaching() {
+  return variations::GetVariationParamValue(
+      kBundledExperimentFieldTrialName,
+      kDisableResultsCachingRule) == "true";
+}
+
+void OmniboxFieldTrial::GetSuggestPollingStrategy(bool* since_the_last_request,
+                                                  int* polling_delay_ms) {
+  *since_the_last_request = variations::GetVariationParamValue(
+      kBundledExperimentFieldTrialName,
+      kSuggestPollingDelaySinceTheLastRequestRule) == "true";

[H Fung, 2014/10/20 21:59:42]

I'm not sure if you want to have a flag to take in when to reset the counter,
such as "keystroke" and "request" instead of using true/false.

[Bart N., 2014/10/22 01:19:08]

I think I'd prefer to stay with the current rule, since we are not planning to
add any new type soon. If so, we can change it easily.

+
+  const std::string& polling_delay_string = variations::GetVariationParamValue(
+      kBundledExperimentFieldTrialName,
+      kSuggestPollingDelayMsRule);
+  if (polling_delay_string.empty() ||
+      !base::StringToInt(polling_delay_string, polling_delay_ms) ||
+      *polling_delay_ms <= 0) {

[Mark P, 2014/10/21 21:28:22]

nit: parans around binary operator <=

[Bart N., 2014/10/22 01:19:07]

Done.

+    // Status Quo (100ms since the last suggest request).

[Mark P, 2014/10/21 21:28:22]

This comment is helpful for reviewers.  For the code, I'd either suggest your
remove it or phrase it differently such as
// Use a default of 100ms since the last suggest request.

(once you see that phrasing, you'll see what I mean when you say it's not
necessary in the code)

[Bart N., 2014/10/22 01:19:08]

Done.

+    *polling_delay_ms = 100;
+  }
+}
+
 const char OmniboxFieldTrial::kBundledExperimentFieldTrialName[] =
     "OmniboxBundledExperimentV1";
 const char OmniboxFieldTrial::kShortcutsScoringMaxRelevanceRule[] =
@@ -355,6 +378,12 @@ const char OmniboxFieldTrial::kAddUWYTMatchEvenIfPromotedURLsRule[] =
     "AddUWYTMatchEvenIfPromotedURLs";
 const char OmniboxFieldTrial::kDisplayHintTextWhenPossibleRule[] =
     "DisplayHintTextWhenPossible";
+const char OmniboxFieldTrial::kDisableResultsCachingRule[] =
+    "DisableResultsCaching";
+const char OmniboxFieldTrial::kSuggestPollingDelaySinceTheLastRequestRule[] =
+    "SuggestPollingDelaySinceTheLastRequest";

[Mark P, 2014/10/21 21:28:22]

If you change the name of the rule, please revise the string here too.

[Bart N., 2014/10/22 01:19:08]

Done.

+const char OmniboxFieldTrial::kSuggestPollingDelayMsRule[] =

[H Fung, 2014/10/20 21:59:42]

This is a param, not a rule?

[Mark P, 2014/10/21 21:28:22]

It's a "rule".  In this file, rule correspond to the key part of the key-value
field that make up the params structure.  The value part of the param variables.
 I know it's weird nomenclature.

[Bart N., 2014/10/22 01:19:08]

Acknowledged.

[Bart N., 2014/10/22 01:19:08]

Acknowledged.

+    "SuggestPollingDelayMs";
 
 const char OmniboxFieldTrial::kHUPNewScoringEnabledParam[] =
     "HUPExperimentalScoringEnabled";