Add support for running host java tests to runtest.

With this change, also refactored runtest as follows: Modified the
test suite schema and python implementation to have an inheritance
structure.  Each test type has its own python module, which will
also handle the logic of running the test.
diff --git a/testrunner/test_defs/test_defs.py b/testrunner/test_defs/test_defs.py
new file mode 100644
index 0000000..7f23b89
--- /dev/null
+++ b/testrunner/test_defs/test_defs.py
@@ -0,0 +1,146 @@
+#!/usr/bin/python2.4
+#
+#
+# Copyright 2008, The Android Open Source Project
+#
+# 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.
+
+"""Parser for test definition xml files."""
+
+# Python imports
+import xml.dom.minidom
+import xml.parsers
+
+# local imports
+import errors
+import logger
+from instrumentation_test import InstrumentationTestSuite
+from native_test import NativeTestSuite
+from host_test import HostTestSuite
+
+
+class TestDefinitions(object):
+  """Accessor for a test definitions xml file data.
+
+  See test_defs.xsd for expected format.
+  """
+
+  def __init__(self):
+    # dictionary of test name to tests
+    self._testname_map = {}
+
+  def __iter__(self):
+    ordered_list = []
+    for k in sorted(self._testname_map):
+      ordered_list.append(self._testname_map[k])
+    return iter(ordered_list)
+
+  def Parse(self, file_path):
+    """Parse the test suite data from from given file path.
+
+    Args:
+      file_path: absolute file path to parse
+    Raises:
+      ParseError if file_path cannot be parsed
+    """
+    try:
+      doc = xml.dom.minidom.parse(file_path)
+      self._ParseDoc(doc)
+    except IOError:
+      logger.Log("test file %s does not exist" % file_path)
+      raise errors.ParseError
+    except xml.parsers.expat.ExpatError:
+      logger.Log("Error Parsing xml file: %s " %  file_path)
+      raise errors.ParseError
+    except errors.ParseError, e:
+      logger.Log("Error Parsing xml file: %s Reason: %s" %  (file_path, e.msg))
+      raise e
+
+  def ParseString(self, xml_string):
+    """Alternate parse method that accepts a string of the xml data."""
+    doc = xml.dom.minidom.parseString(xml_string)
+    # TODO: catch exceptions and raise ParseError
+    return self._ParseDoc(doc)
+
+  def _ParseDoc(self, doc):
+    root_element = self._GetRootElement(doc)
+    for element in root_element.childNodes:
+      if element.nodeType != xml.dom.Node.ELEMENT_NODE:
+        continue
+      test_suite = None
+      if element.nodeName == InstrumentationTestSuite.TAG_NAME:
+        test_suite = InstrumentationTestSuite()
+      elif element.nodeName == NativeTestSuite.TAG_NAME:
+        test_suite = NativeTestSuite()
+      elif element.nodeName == HostTestSuite.TAG_NAME:
+        test_suite = HostTestSuite()
+      else:
+        logger.Log("Unrecognized tag %s found" % element.nodeName)
+        continue
+      test_suite.Parse(element)
+      self._AddTest(test_suite)
+
+  def _GetRootElement(self, doc):
+    root_elements = doc.getElementsByTagName("test-definitions")
+    if len(root_elements) != 1:
+      error_msg = "expected 1 and only one test-definitions tag"
+      raise errors.ParseError(msg=error_msg)
+    return root_elements[0]
+
+  def _AddTest(self, test):
+    """Adds a test to this TestManifest.
+
+    If a test already exists with the same name, it overrides it.
+
+    Args:
+      test: TestSuite to add
+    """
+    if self.GetTest(test.GetName()) is not None:
+      logger.Log("Overriding test definition %s" % test.GetName())
+    self._testname_map[test.GetName()] = test
+
+  def GetTests(self):
+    return self._testname_map.values()
+
+  def GetContinuousTests(self):
+    con_tests = []
+    for test in self.GetTests():
+      if test.IsContinuous():
+        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)
+
+
+def Parse(file_path):
+  """Parses out a TestDefinitions from given path to xml file.
+
+  Args:
+    file_path: string absolute file path
+  Returns:
+    a TestDefinitions object containing data parsed from file_path
+  Raises:
+    ParseError if xml format is not recognized
+  """
+  tests_result = TestDefinitions()
+  tests_result.Parse(file_path)
+  return tests_result