[android] Use ReadFile w/ root permissions for gtest xml file handling.

BUG=646677

Review-Url: https://codereview.chromium.org/2453993002
Cr-Commit-Position: refs/heads/master@{#427911}

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

@@ -7,7 +7,6 @@
 import logging
 import os
 import posixpath
-import tempfile
 
 from devil.android import device_errors
 from devil.android import device_temp_file
@@ -348,40 +347,38 @@ def _RunTest(self, device, test):
     # Run the test.
     timeout = (self._test_instance.shard_timeout
                * self.GetTool(device).GetTimeoutScale())
-    with tempfile.NamedTemporaryFile(suffix='.xml') as host_tmp_results_file:
-      with device_temp_file.DeviceTempFile(
-          adb=device.adb,
-          dir=self._delegate.ResultsDirectory(device),
-          suffix='.xml') as device_tmp_results_file:
-
-        flags = self._test_instance.test_arguments or ''
-        if self._test_instance.enable_xml_result_parsing:
-          flags += ' --gtest_output=xml:%s' % device_tmp_results_file.name
-
-        output = self._delegate.Run(
-            test, device, flags=flags,
-            timeout=timeout, retries=0)
-
-        if self._test_instance.enable_xml_result_parsing:
-          device.PullFile(
-              device_tmp_results_file.name,
-              host_tmp_results_file.name)
-
-      for s in self._servers[str(device)]:
-        s.Reset()
-      if self._test_instance.app_files:
-        self._delegate.PullAppFiles(device, self._test_instance.app_files,
-                                    self._test_instance.app_file_dir)
-      if not self._env.skip_clear_data:
-        self._delegate.Clear(device)
-
-      # Parse the output.
-      # TODO(jbudorick): Transition test scripts away from parsing stdout.
+    with device_temp_file.DeviceTempFile(
+        adb=device.adb,
+        dir=self._delegate.ResultsDirectory(device),
+        suffix='.xml') as device_tmp_results_file:
+
+      flags = self._test_instance.test_arguments or ''
       if self._test_instance.enable_xml_result_parsing:
-        with open(host_tmp_results_file.name) as xml_results_file:
-          results = gtest_test_instance.ParseGTestXML(xml_results_file.read())
-      else:
-        results = gtest_test_instance.ParseGTestOutput(output)
+        flags += ' --gtest_output=xml:%s' % device_tmp_results_file.name
+
+      output = self._delegate.Run(
+          test, device, flags=flags,
+          timeout=timeout, retries=0)
+
+      if self._test_instance.enable_xml_result_parsing:
+        gtest_xml = device.ReadFile(
+            device_tmp_results_file.name,
+            as_root=True)
+
+    for s in self._servers[str(device)]:
+      s.Reset()
+    if self._test_instance.app_files:
+      self._delegate.PullAppFiles(device, self._test_instance.app_files,
+                                  self._test_instance.app_file_dir)
+    if not self._env.skip_clear_data:
+      self._delegate.Clear(device)
+
+    # Parse the output.
+    # TODO(jbudorick): Transition test scripts away from parsing stdout.
+    if self._test_instance.enable_xml_result_parsing:
+      results = gtest_test_instance.ParseGTestXML(gtest_xml)
+    else:
+      results = gtest_test_instance.ParseGTestOutput(output)
 
     # Check whether there are any crashed testcases.
     self._crashes.update(r.GetName() for r in results