Allow getting _only_ personalized snippets for NTP.

components/ntp_snippets/ntp_snippets_fetcher.cc

Index: components/ntp_snippets/ntp_snippets_fetcher.cc
diff --git a/components/ntp_snippets/ntp_snippets_fetcher.cc b/components/ntp_snippets/ntp_snippets_fetcher.cc
index 90c0815a07fc567c7c4715e068af69e5bfc0bd0a..7b73e11a113d7c491ea3ec96dc39bc6318b5b008 100644
--- a/components/ntp_snippets/ntp_snippets_fetcher.cc
+++ b/components/ntp_snippets/ntp_snippets_fetcher.cc
@@ -50,11 +50,16 @@ const char kAuthorizationRequestHeaderFormat[] = "Bearer %s";
 
 // Variation parameter for the variant of fetching to use.
 const char kVariantName[] = "fetching_variant";

[Marc Treib, 2016/05/12 08:59:16]

Also here: s/variant/personalization, or whatever you end up calling it.

[jkrcal, 2016/05/12 09:57:29]

Done.

+const char kHostRestrictionName[] = "fetching_host_restrict";
 
 // Constants listing possible values of the "fetching_variant" parameter.
-const char kVariantRestrictedString[] = "restricted";
 const char kVariantPersonalizedString[] = "personalized";
-const char kVariantRestrictedPersonalizedString[] = "restricted_personalized";
+const char kVariantNonPersonalizedString[] = "non-personalized";
+const char kVariantAllString[] = "all";
+
+// Constants listing possible values of the "fetching_host_restrict" parameter.
+const char kHostRestrictionOnString[] = "on";
+const char kHostRestrictionOffString[] = "off";
 
 const char kRequestParameterFormat[] =
     "{"
@@ -63,7 +68,7 @@ const char kRequestParameterFormat[] =
     "  \"advanced_options\": {"
     "    \"local_scoring_params\": {"
     "      \"content_params\": {"
-    "        \"only_return_personalized_results\": false"
+    "        \"only_return_personalized_results\": %s"
     "%s"  // If authenticated - user segment (lang code) will be inserted here.
     "      },"
     "      \"content_restricts\": {"
@@ -94,6 +99,8 @@ const char kHostRestrictFormat[] =
     "        \"type\": \"HOST_RESTRICT\","
     "        \"value\": \"%s\""
     "      }";
+const char kTrueString[] = "true";
+const char kFalseString[] = "false";
 
 std::string FetchResultToString(NTPSnippetsFetcher::FetchResult result) {
   switch (result) {
@@ -136,15 +143,25 @@ NTPSnippetsFetcher::NTPSnippetsFetcher(
   // Parse the variation parameters and set the defaults if missing.
   std::string variant = variations::GetVariationParamValue(
       ntp_snippets::kStudyName, kVariantName);
-  if (variant == kVariantRestrictedString) {
-    variant_ = Variant::kRestricted;
+  if (variant == kVariantNonPersonalizedString) {
+    variant_ = Variant::kNonPersonalized;
   } else if (variant == kVariantPersonalizedString) {
     variant_ = Variant::kPersonalized;
   } else {
-    variant_ = Variant::kRestrictedPersonalized;
-    LOG_IF(WARNING,
-           !variant.empty() && variant != kVariantRestrictedPersonalizedString)
-        << "Unknown fetching variant provided: " << variant;
+    variant_ = Variant::kAll;
+    LOG_IF(WARNING, !variant.empty() && variant != kVariantAllString)
+        << "Unknown value for fetching_variant: " << variant;
+  }
+
+  std::string host_restriction = variations::GetVariationParamValue(
+      ntp_snippets::kStudyName, kHostRestrictionName);
+  if (host_restriction == kHostRestrictionOffString) {
+    use_host_restriction_ = false;
+  } else {
+    use_host_restriction_ = true;
+    LOG_IF(WARNING, !host_restriction.empty() &&
+                        host_restriction != kHostRestrictionOnString)
+        << "Unknown value for fetching_host_restrict: " << host_restriction;
   }
 }
 
@@ -236,15 +253,13 @@ std::string NTPSnippetsFetcher::GetHostRestricts() const {
 }
 
 bool NTPSnippetsFetcher::UseHostRestriction() const {
-  return (variant_ == Variant::kRestricted ||
-          variant_ == Variant::kRestrictedPersonalized) &&
+  return use_host_restriction_ &&
          !base::CommandLine::ForCurrentProcess()->HasSwitch(
              switches::kDontRestrict);
 }
 
 bool NTPSnippetsFetcher::UseAuthentication() const {
-  return (variant_ == Variant::kPersonalized ||
-          variant_ == Variant::kRestrictedPersonalized);
+  return (variant_ == Variant::kPersonalized || variant_ == Variant::kAll);
 }
 
 void NTPSnippetsFetcher::FetchSnippetsNonAuthenticated() {
@@ -257,8 +272,10 @@ void NTPSnippetsFetcher::FetchSnippetsNonAuthenticated() {
 
   FetchSnippetsImpl(
       url, std::string(),
-      base::StringPrintf(kRequestParameterFormat, "", "",
-                         GetHostRestricts().c_str(), count_to_fetch_));
+      base::StringPrintf(kRequestParameterFormat, /*obfuscated_gaia_id=*/"",
+                         /* only_return_personalized_results=*/kFalseString,
+                         /*user_segment=*/"", GetHostRestricts().c_str(),
+                         count_to_fetch_));
 }
 
 void NTPSnippetsFetcher::FetchSnippetsAuthenticated(
@@ -273,6 +290,7 @@ void NTPSnippetsFetcher::FetchSnippetsAuthenticated(
       base::StringPrintf(kAuthorizationRequestHeaderFormat,
                          oauth_access_token.c_str()),
       base::StringPrintf(kRequestParameterFormat, auth.c_str(),

[Marc Treib, 2016/05/12 08:59:16]

Maybe make a BuildRequestParameter helper function?

[jkrcal, 2016/05/12 09:57:28]

Done.

+                         variant_ == Variant::kAll ? kFalseString : kTrueString,

[Marc Treib, 2016/05/12 08:59:16]

Ah, so when we get here, the variant can't be kNonPersonalized anymore, right?
Still, I'd find it easier to read if this said
variant_ == kPersonalized ? kTrue : kFalse
which should be equivalent, right?

[jkrcal, 2016/05/12 09:57:29]

Done.

                          user_segment.c_str(), GetHostRestricts().c_str(),
                          count_to_fetch_));
 }