Basic android app implementation

tools/telemetry/telemetry/core/backends/android_app_backend.py

Index: tools/telemetry/telemetry/core/backends/android_app_backend.py
diff --git a/tools/telemetry/telemetry/core/backends/android_app_backend.py b/tools/telemetry/telemetry/core/backends/android_app_backend.py
index ddd84688b458fc971aafe2c967044cc2f2f6b5c2..bad80008b0a06d22bdb6ec27b96d921f633538d7 100644
--- a/tools/telemetry/telemetry/core/backends/android_app_backend.py
+++ b/tools/telemetry/telemetry/core/backends/android_app_backend.py
@@ -3,8 +3,29 @@
 # found in the LICENSE file.
 
 from telemetry.core.backends import app_backend
+from telemetry.core.platform import android_platform_backend as \
+  android_platform_backend_module
 
 
 class AndroidAppBackend(app_backend.AppBackend):
-  def __init__(self):
-    super(AndroidAppBackend, self).__init__()
+  def __init__(self, android_platform_backend, start_intent):
+    super(AndroidAppBackend, self).__init__(app_type=start_intent.package)
+    assert isinstance(android_platform_backend,
+                      android_platform_backend_module.AndroidPlatformBackend)
+    self._android_platform_backend = android_platform_backend
+    self._start_intent = start_intent
+
+  @property
+  def _adb(self):
+    return self._android_platform_backend.adb
+
+  def Start(self):
+    """Start an Android app and wait for it to finish launching.
+
+    AppStory derivations can customize the wait-for-ready-state to wait
+    for a more specific event if needed.
+    """
+    self._adb.device().StartActivity(self._start_intent, blocking=True)
+
+  def Close(self):
+    self._android_platform_backend.KillApplication(self._start_intent.package)