ftrace_reader: Mock code that runs atrace for testing

Change-Id: I5601e87fc03ba0b9b499d7224a6ec231230ca9e4
diff --git a/Android.bp b/Android.bp
index aa0101a..a451202 100644
--- a/Android.bp
+++ b/Android.bp
@@ -33,6 +33,7 @@
     "src/base/thread_checker.cc",
     "src/base/unix_task_runner.cc",
     "src/base/watchdog.cc",
+    "src/ftrace_reader/atrace_wrapper.cc",
     "src/ftrace_reader/cpu_reader.cc",
     "src/ftrace_reader/event_info.cc",
     "src/ftrace_reader/event_info_constants.cc",
@@ -227,6 +228,7 @@
     "src/base/thread_checker.cc",
     "src/base/unix_task_runner.cc",
     "src/base/watchdog.cc",
+    "src/ftrace_reader/atrace_wrapper.cc",
     "src/ftrace_reader/cpu_reader.cc",
     "src/ftrace_reader/end_to_end_integrationtest.cc",
     "src/ftrace_reader/event_info.cc",
@@ -2958,6 +2960,7 @@
     "src/base/watchdog.cc",
     "src/base/watchdog_unittest.cc",
     "src/base/weak_ptr_unittest.cc",
+    "src/ftrace_reader/atrace_wrapper.cc",
     "src/ftrace_reader/cpu_reader.cc",
     "src/ftrace_reader/cpu_reader_unittest.cc",
     "src/ftrace_reader/event_info.cc",