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

chrome/browser/profiles/profile.cc

Index: chrome/browser/profiles/profile.cc
diff --git a/chrome/browser/profiles/profile.cc b/chrome/browser/profiles/profile.cc
index c8f14b2eb5917e9edbe9670540c927207e106e72..438639bed5f9ca2c261befc036c9e6cd6d9c9334 100644
--- a/chrome/browser/profiles/profile.cc
+++ b/chrome/browser/profiles/profile.cc
@@ -176,6 +176,10 @@ void Profile::RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
 #if defined(OS_CHROMEOS)
   registry->RegisterBooleanPref(prefs::kAllowScreenLock, true);
 #endif
+
+#if defined(OS_WIN) || defined(OS_LINUX)

[Matt Giuca, 2017/01/23 03:00:57]

I don't think this OS check is appropriate. If we want to add a new OS to WST
later it will be hard to track down all these conditions. We *maybe* should add
a new flag for WST, but I've had a lot of trouble with those in the past (if
needed through a lot of the codebase). I'd rather just leave this open -- it
doesn't matter if it's registered on other platforms (it just won't be used).

[constantina, 2017/01/24 02:03:42]

Done.

+  registry->RegisterDictionaryPref(prefs::kWebShareVisitedTargets);
+#endif
 }
 
 std::string Profile::GetDebugName() {