Update from https://crrev.com/306706

build/android/buildbot/bb_device_steps.py

Index: build/android/buildbot/bb_device_steps.py
diff --git a/build/android/buildbot/bb_device_steps.py b/build/android/buildbot/bb_device_steps.py
index 3ca0f4d0d01a662e5a4a1ad59dbbd8f7f7e69b52..49e6a4818785fc06ebde8dd5c5c6c0aded6c173c 100755
--- a/build/android/buildbot/bb_device_steps.py
+++ b/build/android/buildbot/bb_device_steps.py
@@ -643,8 +643,9 @@ def MainTestWrapper(options):
       cmd(options)
 
     if options.install:
-      test_obj = INSTRUMENTATION_TESTS[options.install]
-      InstallApk(options, test_obj, print_step=True)
+      for i in options.install:
+        test_obj = INSTRUMENTATION_TESTS[i]
+        InstallApk(options, test_obj, print_step=True)
 
     if options.test_filter:
       bb_utils.RunSteps(options.test_filter, GetTestStepCmds(), options)
@@ -683,7 +684,7 @@ def GetDeviceStepsOptParser():
   parser.add_option('--gtest-filter',
                     help='Filter for running a subset of tests of a gtest test')
   parser.add_option('--asan', action='store_true', help='Run tests with asan.')
-  parser.add_option('--install', metavar='<apk name>',
+  parser.add_option('--install', metavar='<apk name>', action="append",
                     help='Install an apk by name')
   parser.add_option('--no-reboot', action='store_true',
                     help='Do not reboot devices during provisioning.')