[WebAuthn] Remove BLE authenticator support UI

This is part of a series of CLs for removing explicit BLE authenticator
support from Chrome. It removes the UI and the plumbing for the UI from
content/ and device/.

Bug: 1046131
Change-Id: Id451d0da8d28b49e9c80038ac2a1b7998307cb35
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2159615
Reviewed-by: Nina Satragno <[email protected]>
Reviewed-by: Evan Stade <[email protected]>
Reviewed-by: Nasko Oskov <[email protected]>
Reviewed-by: Dominic Battré <[email protected]>
Reviewed-by: Martin Kreichgauer <[email protected]>
Commit-Queue: Ken Buchanan <[email protected]>
Cr-Commit-Position: refs/heads/master@{#762568}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 65ccec7..e29a6c98 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -464,9 +464,10 @@
 // on other platforms.
 const char kWebAuthnLastTransportUsedPrefName[] =
     "webauthn.last_transport_used";
+#endif  // defined(OS_ANDROID)
+// Deprecated 4/2020
 const char kWebAuthnBlePairedMacAddressesPrefName[] =
     "webauthn.ble.paired_mac_addresses";
-#endif  // defined(OS_ANDROID)
 
 // Deprecated 7/2019
 const char kLastKnownGoogleURL[] = "browser.last_known_google_url";
@@ -583,8 +584,8 @@
 #if defined(OS_ANDROID)
   registry->RegisterStringPref(kWebAuthnLastTransportUsedPrefName,
                                std::string());
-  registry->RegisterListPref(kWebAuthnBlePairedMacAddressesPrefName);
 #endif  // defined(OS_ANDROID)
+  registry->RegisterListPref(kWebAuthnBlePairedMacAddressesPrefName);
 
   registry->RegisterStringPref(kLastKnownGoogleURL, std::string());
   registry->RegisterStringPref(kLastPromptedGoogleURL, std::string());
@@ -1184,8 +1185,9 @@
 #if defined(OS_ANDROID)
   // Added 7/2019.
   profile_prefs->ClearPref(kWebAuthnLastTransportUsedPrefName);
-  profile_prefs->ClearPref(kWebAuthnBlePairedMacAddressesPrefName);
 #endif  // defined(OS_ANDROID)
+  // Added 4/2020.
+  profile_prefs->ClearPref(kWebAuthnBlePairedMacAddressesPrefName);
 
   // Added 7/2019.
 #if defined(USE_X11)