[Android] Fix checksum handling when md5sum generates unexpected output.

build/android/pylib/instrumentation/instrumentation_test_instance.py

Index: build/android/pylib/instrumentation/instrumentation_test_instance.py
diff --git a/build/android/pylib/instrumentation/instrumentation_test_instance.py b/build/android/pylib/instrumentation/instrumentation_test_instance.py
index 3f56e6d99f90007caf457e5eb3fde6b608afbecf..ccc0e728602042a8d5c8efeeef4889b20bfe6304 100644
--- a/build/android/pylib/instrumentation/instrumentation_test_instance.py
+++ b/build/android/pylib/instrumentation/instrumentation_test_instance.py
@@ -335,7 +335,7 @@ class InstrumentationTestInstance(test_instance.TestInstance):
 
     with open(pickle_path, 'r') as pickle_file:
       pickle_data = pickle.loads(pickle_file.read())
-    jar_md5, _ = md5sum.CalculateHostMd5Sums(jar_path)[0]
+    jar_md5 = md5sum.CalculateHostMd5Sums(jar_path)[jar_path]

[perezju, 2015/04/24 08:06:32]

This usage seems pretty common. Wondering if we should add a function in md5sum,
something like:

def CalculateHostMd5Sum(path):
  return CalculateHostMd5Sums(path).get(path)

[jbudorick, 2015/04/24 13:56:36]

It only seems common because our instrumentation code is temporarily duplicated.

 
     try:
       if pickle_data['VERSION'] != _PICKLE_FORMAT_VERSION:
@@ -377,7 +377,7 @@ class InstrumentationTestInstance(test_instance.TestInstance):
             if is_test_class(c)]
 
   def _SaveTestsToPickle(self, pickle_path, jar_path, tests):
-    jar_md5, _ = md5sum.CalculateHostMd5Sums(jar_path)[0]
+    jar_md5 = md5sum.CalculateHostMd5Sums(jar_path)[jar_path]
     pickle_data = {
       'VERSION': _PICKLE_FORMAT_VERSION,
       'JAR_MD5SUM': jar_md5,