Deobfuscate instrumentation test output

Adds a new GN arg "enable_proguard_obfuscation_for_tests", which enables
obfuscation for chrome instrumentation tests even when
enable_proguard_obfuscation = false.

Updates test_runner.py to filter instrumentation output through
java_deobfuscate (but not yet logcat).

Updates java_deobfuscate's regex to match:
  INSTRUMENTATION_STATUS: class=bNs

Bug: 713710
Change-Id: I569dd62f051a041be2ec16664c5f714cb9857453
Reviewed-on: https://chromium-review.googlesource.com/614988
Commit-Queue: Andrew Grieve <[email protected]>
Reviewed-by: John Budorick <[email protected]>
Cr-Commit-Position: refs/heads/master@{#499714}
diff --git a/build/android/test_runner.pydeps b/build/android/test_runner.pydeps
index 573577e..cd1f494 100644
--- a/build/android/test_runner.pydeps
+++ b/build/android/test_runner.pydeps
@@ -174,6 +174,7 @@
 pylib/results/json_results.py
 pylib/results/report_results.py
 pylib/symbols/__init__.py
+pylib/symbols/deobfuscator.py
 pylib/symbols/stack_symbolizer.py
 pylib/utils/__init__.py
 pylib/utils/decorators.py