[EasyUnlock] Observe proximity changes and clean up TX power strategy.

chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc

Index: chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc
diff --git a/chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc b/chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc
index 8e27ad7b1f0dfb959accaa84464cd1368aa9cbea..9e42d15c56a99cb6fe57c026fd1276af0331ddd0 100644
--- a/chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc
+++ b/chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc
@@ -100,11 +100,11 @@ ScreenlockState ToScreenlockState(easy_unlock_private::State state) {
     case easy_unlock_private::STATE_PHONE_UNSUPPORTED:
       return ScreenlockState::PHONE_UNSUPPORTED;
     case easy_unlock_private::STATE_RSSI_TOO_LOW:
-      return ScreenlockState::RSSI_TOO_LOW;
     case easy_unlock_private::STATE_TX_POWER_TOO_HIGH:
-      return ScreenlockState::TX_POWER_TOO_HIGH;
+      // Note: TX Power is deprecated, so we merge it with the RSSI state.
+      return ScreenlockState::RSSI_TOO_LOW;
     case easy_unlock_private::STATE_PHONE_LOCKED_AND_TX_POWER_TOO_HIGH:
-      return ScreenlockState::PHONE_LOCKED_AND_TX_POWER_TOO_HIGH;
+      return ScreenlockState::PHONE_LOCKED_AND_RSSI_TOO_LOW;
     case easy_unlock_private::STATE_AUTHENTICATED:
       return ScreenlockState::AUTHENTICATED;
     default: