Insert logcat as part of test result for android instrumentation tests.

build/android/pylib/local/device/local_device_instrumentation_test_run.py

Index: build/android/pylib/local/device/local_device_instrumentation_test_run.py
diff --git a/build/android/pylib/local/device/local_device_instrumentation_test_run.py b/build/android/pylib/local/device/local_device_instrumentation_test_run.py
index 6c00b7087dc9f5c44aeabdc2ca2abe8a17c0174c..94a51428d394aef7829e8eef7cfdfba551c354b9 100644
--- a/build/android/pylib/local/device/local_device_instrumentation_test_run.py
+++ b/build/android/pylib/local/device/local_device_instrumentation_test_run.py
@@ -263,8 +263,13 @@ class LocalDeviceInstrumentationTestRun(
           check_return=True)
       time_ms = lambda: int(time.time() * 1e3)
       start_ms = time_ms()
-      output = device.StartInstrumentation(
-          target, raw=True, extras=extras, timeout=timeout, retries=0)
+      logcat = ''
+      with device.GetLogcatMonitor() as logmon:
+        output = device.StartInstrumentation(
+            target, raw=True, extras=extras, timeout=timeout, retries=0)
+        for logstring in logmon.FindAll(r'.*'):

[jbudorick, 2016/10/25 02:17:35]

There are a couple of better options for dumping the entire logcat:
 - create a logcat monitor w/ a temporary file, then read that file after the
logcat monitor context manager goes out of scope.
 - add a new function to logcat monitor that returns the entire recorded logcat
up to that point.

I think I prefer the former to the latter.

[BigBossZhiling, 2016/10/25 22:08:44]

Done.

+           logcat += logstring.group(0) + '\n'
+      logmon.Close()
     finally:
       device.RunShellCommand(
           ['log', '-p', 'i', '-t', _TAG, 'END %s' % test_name],
@@ -281,7 +286,7 @@ class LocalDeviceInstrumentationTestRun(
     result_code, result_bundle, statuses = (
         self._test_instance.ParseAmInstrumentRawOutput(output))
     results = self._test_instance.GenerateTestResults(
-        result_code, result_bundle, statuses, start_ms, duration_ms)
+        result_code, result_bundle, statuses, start_ms, duration_ms, logcat)
 
     # Update the result name if the test used flags.
     if flags: