Move functionality only used by ZeroSuggestProvider out of BaseSearchProvider.

This requires exposing a previously-local-to-the-file function as protected, but
this seems like an OK tradeoff.

In the process, also rejiggered a few things (e.g. eliminated a file-scope using
directive).

BUG=none
TEST=none

Change-Id: I5fafda5ce264370cbe6d67e39f24c58fef7543ee
Reviewed-on: https://chromium-review.googlesource.com/792123
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519530}

components/omnibox/browser/base_search_provider.cc

@@ -26,23 +26,9 @@
 #include "net/traffic_annotation/network_traffic_annotation.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
-#include "third_party/metrics_proto/omnibox_event.pb.h"
 #include "third_party/metrics_proto/omnibox_input_type.pb.h"
 #include "url/gurl.h"
 
-using metrics::OmniboxEventProto;
-
-namespace {
-bool IsNTPPage(OmniboxEventProto::PageClassification page_classification) {
-  return (page_classification == OmniboxEventProto::NTP) ||
-         (page_classification == OmniboxEventProto::OBSOLETE_INSTANT_NTP) ||
-         (page_classification ==
-          OmniboxEventProto::INSTANT_NTP_WITH_FAKEBOX_AS_STARTING_FOCUS) ||
-         (page_classification ==
-          OmniboxEventProto::INSTANT_NTP_WITH_OMNIBOX_AS_STARTING_FOCUS);
-}
-}  // namespace
-
 // SuggestionDeletionHandler -------------------------------------------------
 
 // This class handles making requests to the server in order to delete
@@ -224,23 +210,14 @@ const char BaseSearchProvider::kFalse[] = "false";
 
 BaseSearchProvider::~BaseSearchProvider() {}
 
-void BaseSearchProvider::SetDeletionURL(const std::string& deletion_url,
-                                        AutocompleteMatch* match) {
-  if (deletion_url.empty())
-    return;
-
-  TemplateURLService* template_url_service = client_->GetTemplateURLService();
-  if (!template_url_service)
-    return;
-  GURL url =
-      template_url_service->GetDefaultSearchProvider()->GenerateSearchURL(
-          template_url_service->search_terms_data());
-  url = url.GetOrigin().Resolve(deletion_url);
-  if (url.is_valid()) {
-    match->RecordAdditionalInfo(BaseSearchProvider::kDeletionUrlKey,
-        url.spec());
-    match->deletable = true;
-  }
+// static
+bool BaseSearchProvider::IsNTPPage(
+    metrics::OmniboxEventProto::PageClassification classification) {
+  using OEP = metrics::OmniboxEventProto;
+  return (classification == OEP::NTP) ||
+         (classification == OEP::OBSOLETE_INSTANT_NTP) ||
+         (classification == OEP::INSTANT_NTP_WITH_FAKEBOX_AS_STARTING_FOCUS) ||
+         (classification == OEP::INSTANT_NTP_WITH_OMNIBOX_AS_STARTING_FOCUS);
 }
 
 // static
@@ -330,29 +307,12 @@ AutocompleteMatch BaseSearchProvider::CreateSearchSuggestion(
   return match;
 }
 
-// static
-bool BaseSearchProvider::ZeroSuggestEnabled(
-    OmniboxEventProto::PageClassification page_classification,
-    const AutocompleteProviderClient* client) {
-  // Don't show zero suggest on the NTP.
-  // TODO(hfung): Experiment with showing MostVisited zero suggest on NTP
-  // under the conditions described in crbug.com/305366.
-  if (IsNTPPage(page_classification))
-    return false;
-
-  // Don't run if in incognito mode.
-  if (client->IsOffTheRecord())
-    return false;
-
-  return true;
-}
-
 // static
 bool BaseSearchProvider::CanSendURL(
     const GURL& current_page_url,
     const GURL& suggest_url,
     const TemplateURL* template_url,
-    OmniboxEventProto::PageClassification page_classification,
+    metrics::OmniboxEventProto::PageClassification page_classification,
     const SearchTermsData& search_terms_data,
     AutocompleteProviderClient* client) {
   // Make sure we are sending the suggest request through a cryptographically
@@ -405,6 +365,25 @@ bool BaseSearchProvider::CanSendURL(
   return true;
 }
 
+void BaseSearchProvider::SetDeletionURL(const std::string& deletion_url,
+                                        AutocompleteMatch* match) {
+  if (deletion_url.empty())
+    return;
+
+  TemplateURLService* template_url_service = client_->GetTemplateURLService();
+  if (!template_url_service)
+    return;
+  GURL url =
+      template_url_service->GetDefaultSearchProvider()->GenerateSearchURL(
+          template_url_service->search_terms_data());
+  url = url.GetOrigin().Resolve(deletion_url);
+  if (url.is_valid()) {
+    match->RecordAdditionalInfo(BaseSearchProvider::kDeletionUrlKey,
+                                url.spec());
+    match->deletable = true;
+  }
+}
+
 void BaseSearchProvider::AddMatchToMap(
     const SearchSuggestionParser::SuggestResult& result,
     const std::string& metadata,

components/omnibox/browser/base_search_provider.h

@@ -102,6 +102,10 @@ class BaseSearchProvider : public AutocompleteProvider {
   typedef std::vector<std::unique_ptr<SuggestionDeletionHandler>>
       SuggestionDeletionHandlers;
 
+  // Returns whether the provided classification indicates some sort of NTP.
+  static bool IsNTPPage(
+      metrics::OmniboxEventProto::PageClassification classification);
+
   // Returns an AutocompleteMatch with the given |autocomplete_provider|
   // for the search |suggestion|, which represents a search via |template_url|.
   // If |template_url| is NULL, returns a match with an invalid destination URL.
@@ -128,15 +132,6 @@ class BaseSearchProvider : public AutocompleteProvider {
       int accepted_suggestion,
       bool append_extra_query_params);
 
-  // Returns whether the requirements for requesting zero suggest results
-  // are met. The requirements are
-  // * The user is enrolled in a zero suggest experiment.
-  // * The user is not on the NTP.
-  // * The user is not in incognito mode. (Incognito disables suggest entirely.)
-  static bool ZeroSuggestEnabled(
-      metrics::OmniboxEventProto::PageClassification page_classification,
-      const AutocompleteProviderClient* client);
-
   // Returns whether we can send the URL of the current page in any suggest
   // requests.  Doing this requires that all the following hold:
   // * The suggest request is sent over HTTPS.  This avoids leaking the current

components/omnibox/browser/zero_suggest_provider.cc

@@ -503,7 +503,14 @@ AutocompleteMatch ZeroSuggestProvider::MatchForCurrentURL() {
 
 bool ZeroSuggestProvider::ShouldShowNonContextualZeroSuggest(
     const GURL& current_page_url) const {
-  if (!ZeroSuggestEnabled(current_page_classification_, client()))
+  // Don't show zero suggest on the NTP.
+  // TODO(hfung): Experiment with showing MostVisited zero suggest on NTP
+  // under the conditions described in crbug.com/305366.
+  if (IsNTPPage(current_page_classification_))
+    return false;
+
+  // Don't run if in incognito mode.
+  if (client()->IsOffTheRecord())
     return false;
 
   // If we cannot send URLs, then only the MostVisited and Personalized