workload: adding basic UIAutomator workload implementation

Added a workload type to handle workloads that have both an APK with an
application and associated automation JAR. Added benchmarkpi
implementation using using the new workload.

wa/workloads/benchmarkpi/__init__.py

@@ -0,0 +1,62 @@
+#    Copyright 2013-2015 ARM Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+
+import re
+
+from wa import ApkUiautoWorkload
+
+
+class BenchmarkPi(ApkUiautoWorkload):
+
+    name = 'benchmarkpi'
+    description = """
+    Measures the time the target device takes to run and complete the Pi
+    calculation algorithm.
+
+    http://androidbenchmark.com/howitworks.php
+
+    from the website:
+
+    The whole idea behind this application is to use the same Pi calculation
+    algorithm on every Android Device and check how fast that proccess is.
+    Better calculation times, conclude to faster Android devices. This way you
+    can also check how lightweight your custom made Android build is. Or not.
+
+    As Pi is an irrational number, Benchmark Pi does not calculate the actual Pi
+    number, but an approximation near the first digits of Pi over the same
+    calculation circles the algorithms needs.
+
+    So, the number you are getting in miliseconds is the time your mobile device
+    takes to run and complete the Pi calculation algorithm resulting in a
+    approximation of the first Pi digits.
+    """
+    package = 'gr.androiddev.BenchmarkPi'
+    activity = '.BenchmarkPi'
+
+    regex = re.compile('You calculated Pi in ([0-9]+)')
+
+    def update_output(self, context):
+        super(BenchmarkPi, self).update_output(context)
+        logcat_file = context.get_artifact_path('logcat')
+        with open(logcat_file) as fh:
+            for line in fh:
+                match = self.regex.search(line)
+                if match:
+                    result = int(match.group(1))
+
+        if result is not None:
+            context.add_metric('pi calculation', result,
+                               'milliseconds', lower_is_better=True)