Update ZPS on NTP prefetch.

The embedded change updates prefetch fake page classification from NTP to
INSTANT_NTP_WITH_OMNIBOX_AS_STARTING_FOCUS to allow the request to be
correctly categorized by ZeroSuggestProvider in cases where
ZeroSuggestVariant:6 parameter (for INSTANT_NTP...) includes RemoteNoUrl
source, whereas ZeroSuggestVariant:1 parameter (for NTP) doesn't.

Bug: 1004932, 1004925
Change-Id: Ia797b490b90f1b596b1e175c91d37c975b0d45e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1861099
Commit-Queue: Ender <ender@google.com>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706197}

chrome/browser/android/omnibox/autocomplete_controller_android.cc

@@ -128,16 +128,18 @@ ZeroSuggestPrefetcher::ZeroSuggestPrefetcher(Profile* profile)
   // Creating an arbitrary fake_request_source to avoid passing in an invalid
   // AutocompleteInput object. This source is ignored entirely when
   // kZeroSuggestionsOnNTP feature flag is enabled.
-  base::string16 fake_request_source =
-      base::ASCIIToUTF16("chrome-native://newtab");
-  auto context = metrics::OmniboxEventProto::NTP;
+  base::string16 fake_request_source = base::ASCIIToUTF16("chrome://newtab");
+  base::string16 fake_omnibox_content;
+  auto context =
+      metrics::OmniboxEventProto::INSTANT_NTP_WITH_OMNIBOX_AS_STARTING_FOCUS;
 
   if (!base::FeatureList::IsEnabled(omnibox::kZeroSuggestionsOnNTP)) {
     fake_request_source = base::ASCIIToUTF16("http://www.foobarbazblah.com");
+    fake_omnibox_content = fake_request_source;
     context = metrics::OmniboxEventProto::OTHER;
   }
 
-  AutocompleteInput input(fake_request_source, context,
+  AutocompleteInput input(fake_omnibox_content, context,
                           ChromeAutocompleteSchemeClassifier(profile));
   input.set_current_url(GURL(fake_request_source));
   input.set_from_omnibox_focus(true);