[Android] Refactor the native test wrappers.

build/android/pylib/utils/apk_helper.py

Index: build/android/pylib/utils/apk_helper.py
diff --git a/build/android/pylib/utils/apk_helper.py b/build/android/pylib/utils/apk_helper.py
index f5e9cd3869ffddb42b7873a6937bc254abc8c89a..6dd209e3dc17960691937220c68c4f1cbadd28ff 100644
--- a/build/android/pylib/utils/apk_helper.py
+++ b/build/android/pylib/utils/apk_helper.py
@@ -19,14 +19,14 @@ _MANIFEST_ELEMENT_RE = re.compile(r'\s*(?:E|N): (\S*) .*$')
 
 def GetPackageName(apk_path):
   """Returns the package name of the apk."""
-  aapt_cmd = [_AAPT_PATH, 'dump', 'badging', apk_path]
-  aapt_output = cmd_helper.GetCmdOutput(aapt_cmd).split('\n')
-  package_name_re = re.compile(r'package: .*name=\'(\S*)\'')
-  for line in aapt_output:
-    m = package_name_re.match(line)
-    if m:
-      return m.group(1)
-  raise Exception('Failed to determine package name of %s' % apk_path)
+  return ApkHelper(apk_path).GetPackageName()
+
+
+# TODO(jbudorick): Deprecate and remove this function once callers have been
+# converted to ApkHelper.GetInstrumentationName
+def GetInstrumentationName(apk_path):
+  """Returns the name of the Instrumentation in the apk."""
+  return ApkHelper(apk_path).GetInstrumentationName()
 
 
 def _ParseManifestFromApk(apk_path):
@@ -65,12 +65,53 @@ def _ParseManifestFromApk(apk_path):
   return parsed_manifest
 
 
-def GetInstrumentationName(
-    apk_path, default='android.test.InstrumentationTestRunner'):
-  """Returns the name of the Instrumentation in the apk."""
+class ApkHelper(object):
+  def __init__(self, apk_path):
+    self._apk_path = apk_path
+    self._manifest = None
+    self._package_name = None
+
+  def GetActivityName(self):
+    """Returns the name of the Activity in the apk."""
+    manifest_info = self._GetManifest()
+    try:
+      activity = (
+          manifest_info['manifest']['application']['activity']
+              ['android:name'][0])
+    except KeyError:
+      return None
+    if '.' not in activity:
+      activity = '%s.%s' % (self.GetPackageName(), activity)
+    elif activity.startswith('.'):
+      activity = '%s%s' % (self.GetPackageName(), activity)
+    return activity
+
+  def GetInstrumentationName(
+      self, default='android.test.InstrumentationTestRunner'):
+    """Returns the name of the Instrumentation in the apk."""
+    manifest_info = self._GetManifest()
+    try:
+      return manifest_info['manifest']['instrumentation']['android:name'][0]
+    except KeyError:
+      return default
+
+  def GetPackageName(self):
+    """Returns the package name of the apk."""
+    if self._package_name:
+      return self._package_name
+
+    aapt_cmd = [_AAPT_PATH, 'dump', 'badging', self._apk_path]
+    aapt_output = cmd_helper.GetCmdOutput(aapt_cmd).split('\n')
+    package_name_re = re.compile(r'package: .*name=\'(\S*)\'')
+    for line in aapt_output:
+      m = package_name_re.match(line)
+      if m:
+        self._package_name = m.group(1)
+        return self._package_name
+    raise Exception('Failed to determine package name of %s' % self._apk_path)
+
+  def _GetManifest(self):
+    if not self._manifest:
+      self._manifest = _ParseManifestFromApk(self._apk_path)
+    return self._manifest
 
-  try:
-    manifest_info = _ParseManifestFromApk(apk_path)
-    return manifest_info['manifest']['instrumentation']['android:name'][0]
-  except KeyError:
-    return default