Add flags for in-app data search and Play Store search.

ArcAppDataSearchProvider used to be created and called
unconditionally which is not optimal.

Play Store search is already protected by a (disabled by default)
feature. Adding a flag makes it easier to debug and test.

Bug: 818902
Test: manual, AboutFlagsHistogramTest
Change-Id: Ifb20d90de4e1f977b320fd4f14079570bff367bf
Reviewed-on: https://chromium-review.googlesource.com/c/1300293
Commit-Queue: Vladislav Kaznacheev <[email protected]>
Reviewed-by: Xiyuan Xia <[email protected]>
Cr-Commit-Position: refs/heads/master@{#603553}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 9de89c4..4553bd7 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -1933,6 +1933,9 @@
 extern const char kEnableAppShortcutSearchName[];
 extern const char kEnableAppShortcutSearchDescription[];
 
+extern const char kEnableAppDataSearchName[];
+extern const char kEnableAppDataSearchDescription[];
+
 extern const char kEnableAppsGridGapFeatureName[];
 extern const char kEnableAppsGridGapFeatureDescription[];
 
@@ -1993,6 +1996,9 @@
 extern const char kEnablePerUserTimezoneName[];
 extern const char kEnablePerUserTimezoneDescription[];
 
+extern const char kEnablePlayStoreSearchName[];
+extern const char kEnablePlayStoreSearchDescription[];
+
 extern const char kEnableSettingsShortcutSearchName[];
 extern const char kEnableSettingsShortcutSearchDescription[];