[omnibox] [bookmark-paths] Add no-op feature, params, & flag.

Currently, bookmark suggestions are limited to title & URL matches. E.g
the input 'planets jupiter' won't suggest a bookmark titled 'jupiter' in
a directory 'planets'.

This is the 1st of 3 CLs implementing bookmark-paths which will allow
inputs to match bookmark paths (without contributing to the bookmark
suggestion's score).

This CL creates 4 params that will support 5 planned UI variations:
1) Title - URL (current behaviour)
2) Title - Path
3) Title : Path - URL
4) Path/Title - URL
5) Title - Path|URL (either path or URL depending on which matched the
input; favor path if both or neither matched the input)

Bug: 1129524
Change-Id: Iba575d8fc7db2fcb8ec9bd9b8c384dac83eaba1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2416931
Reviewed-by: Tommy Li <[email protected]>
Commit-Queue: manuk hovanesian <[email protected]>
Cr-Commit-Position: refs/heads/master@{#812784}
diff --git a/components/omnibox/common/omnibox_features.cc b/components/omnibox/common/omnibox_features.cc
index ddf350b..20404974 100644
--- a/components/omnibox/common/omnibox_features.cc
+++ b/components/omnibox/common/omnibox_features.cc
@@ -304,6 +304,13 @@
     "OmniboxHistoryQuickProviderAllowMidwordContinuations",
     base::FEATURE_ENABLED_BY_DEFAULT};
 
+// If enabled, inputs may match bookmark paths. These path matches won't
+// contribute to scoring. E.g. 'planets jupiter' can suggest a bookmark titled
+// 'Jupiter' with URL 'en.wikipedia.org/wiki/Jupiter' located in a path
+// containing 'planet.'
+const base::Feature kBookmarkPaths{"OmniboxBookmarkPaths",
+                                   base::FEATURE_DISABLED_BY_DEFAULT};
+
 // If enabled, shows slightly more compact suggestions, allowing the
 // kAdaptiveSuggestionsCount feature to fit more suggestions on screen.
 const base::Feature kCompactSuggestions{"OmniboxCompactSuggestions",