Add a pref name for share targets, and store their manifest data.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 01658e3491d08b4e8c2ee7e054aaf655d41363c1..5a683cfdcaf61faa4d8d08f7fc8d1020d6012140 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -2373,4 +2373,10 @@ const char kSearchGeolocationPostDisclosureMetricsRecorded[] =
 // default search engine, if it is the Google search engine.
 const char kGoogleDSEGeolocationSetting[] = "google_dse_geolocation_setting";
 
+// A dictionary of manifest URLs of Web Share Targets to a dictionary containing
+// attributes of its share_target field found in its manifest. Each key in the
+// dictionary is the name of the attribute, and the value is the corresponding
+// value.
+const char kWebShareVisitedTargets[] = "profile.web_share.visited_targets";
+
 }  // namespace prefs