Revert of Revert of [Easy Unlock] Port the BluetoothConnectionFinder class to native code.

components/proximity_auth/BUILD.gn

Index: components/proximity_auth/BUILD.gn
diff --git a/components/proximity_auth/BUILD.gn b/components/proximity_auth/BUILD.gn
index caf35b416316f1d4a7f71b83c4451d5c586dd07e..edba900a5061f57a00035dbbd9b6eec988c9f7f8 100644
--- a/components/proximity_auth/BUILD.gn
+++ b/components/proximity_auth/BUILD.gn
@@ -6,11 +6,14 @@
   sources = [
     "bluetooth_connection.cc",
     "bluetooth_connection.h",
+    "bluetooth_connection_finder.cc",
+    "bluetooth_connection_finder.h",
     "bluetooth_util.cc",
     "bluetooth_util_chromeos.cc",
     "bluetooth_util.h",
     "connection.cc",
     "connection.h",
+    "connection_finder.h",
     "connection_observer.h",
     "proximity_auth_system.cc",
     "proximity_auth_system.h",
@@ -32,6 +35,7 @@
   testonly = true
   sources = [
     "bluetooth_connection_unittest.cc",
+    "bluetooth_connection_finder_unittest.cc",
     "connection_unittest.cc",
     "proximity_auth_system_unittest.cc",
     "remote_status_update_unittest.cc",
@@ -51,11 +55,6 @@
 # Note: This is a convenience target for ease of rapid iteration during
 # development. It is not executed on any try or build bots.
 test("proximity_auth_unittests") {
-  sources = [
-    "run_all_unittests.cc",
-  ]
-  
-  deps = [
-    ":unit_tests",
-  ]
+  sources = [ "run_all_unittests.cc" ]
+  deps = [ ":unit_tests" ]
 }