Overhaul Mandoline event transport code

mojo/converters/input_events/tests/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("logging") {
-  sources = [
-    "log_buffer.cc",
-    "log_buffer.h",
-    "logging.cc",
-    "logging.h",
+import("//testing/test.gni")
+
+test("input_events_lib_unittests") {
+  deps = [
+    "//base",
+    "//base/test:test_support",
+    "//mojo/converters/input_events",
+    "//testing/gtest",
+    "//third_party/mojo/src/mojo/edk/test:run_all_unittests",
+    "//components/html_viewer:lib",
   ]
 
-  deps = [
-    "//base",
+  sources = [
+    "input_events_unittest.cc",
   ]
 }
-
-source_set("unit_tests") {
-  testonly = true
-  sources = [
-    "logging_unittest.cc",
-  ]
-
-  deps = [
-    "//base/test:test_support",
-    "//testing/gtest",
-  ]
-}