Initial change to add cts tests to runtest.

Adds cts test definitions to the testrunner/test_defs.xml.
Adds support for runtest --cts arg, which will run all cts tests.
This temporarily relies on the addition of a 'cts' attribute to the test
definition - a new xml format may be defined later that changes how cts tests
are identified.

This change is based on previous unsubmitted CL
https://android-git.corp.google.com/g/Gerrit#change,1702. The only delta wrt
to that change is the use of InstrumentationCtsTestRunner.

Update: rebased to latest donut.

testrunner/test_defs.py

@@ -144,6 +144,14 @@ class TestDefinitions(object):
         con_tests.append(test)
     return con_tests
 
+  def GetCtsTests(self):
+    """Return list of cts tests."""
+    cts_tests = []
+    for test in self.GetTests():
+      if test.IsCts():
+        cts_tests.append(test)
+    return cts_tests
+
   def GetTest(self, name):
     return self._testname_map.get(name, None)
   
@@ -157,6 +165,7 @@ class TestSuite(object):
   _TARGET_ATTR = "coverage_target"
   _BUILD_ATTR = "build_path"
   _CONTINUOUS_ATTR = "continuous"
+  _CTS_ATTR = "cts"
   _DESCRIPTION_ATTR = "description"
   _EXTRA_MAKE_ARGS_ATTR = "extra_make_args"
 
@@ -199,6 +208,11 @@ class TestSuite(object):
       self._continuous = suite_element.getAttribute(self._CONTINUOUS_ATTR)
     else:
       self._continuous = False
+    if suite_element.hasAttribute(self._CTS_ATTR):
+      self._cts = suite_element.getAttribute(self._CTS_ATTR)
+    else:
+      self._cts = False
+
     if suite_element.hasAttribute(self._DESCRIPTION_ATTR):
       self._description = suite_element.getAttribute(self._DESCRIPTION_ATTR)
     else:
@@ -236,6 +250,10 @@ class TestSuite(object):
     """Returns true if test is flagged as being part of the continuous tests"""  
     return self._continuous
 
+  def IsCts(self):
+    """Returns true if test is part of the compatibility test suite"""
+    return self._cts
+
   def IsNative(self):
     """Returns true if test is a native one."""
     return self._native