Add Android-backend to the memory_inspector (prerequisites).

tools/memory_inspector/tests/mock_adb/mock_adb.py

Index: tools/memory_inspector/tests/mock_adb/mock_adb.py
diff --git a/tools/memory_inspector/tests/mock_adb/mock_adb.py b/tools/memory_inspector/tests/mock_adb/mock_adb.py
new file mode 100644
index 0000000000000000000000000000000000000000..c514b0f53a3848ab36fdddeef0498cfe8e97b698
--- /dev/null
+++ b/tools/memory_inspector/tests/mock_adb/mock_adb.py
@@ -0,0 +1,36 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import json
+import os
+import tempfile
+
+
+class MockAdb(object):
+  """Simple and effective mock for Android adb.
+
+  This module is meant to be used in integration tests in conjunction with the
+  other script named 'adb' living in the same directory.
+  The purpose of this class is preparing a dictionary of mocked responses to adb
+  commands. The dictionary is stored into a json file and read by the mock 'adb'
+  script. The path of the json dict is held in the MOCK_ADB_CFG env var.
+  """
+
+  def __init__(self):
+    self._responses = {}  # Maps expected_cmd (str) -> prepared_response (str).
+    self._cfg_file = None
+
+  def Start(self):
+    (fd_num, self._cfg_file) = tempfile.mkstemp()
+    with os.fdopen(fd_num, 'w') as f:
+      json.dump(self._responses, f)
+      f.close()
+    os.environ['MOCK_ADB_CFG'] = self._cfg_file
+
+  def Stop(self):
+    assert(self._cfg_file), 'Stop called before Start.'
+    os.unlink(self._cfg_file)
+
+  def PrepareResponse(self, cmd, response):
+    self._responses[cmd] = response