Add bisect-config-trying script and a few example configs.

tools/auto_bisect/configs/android.bisect.blink_perf.cfg

Index: tools/auto_bisect/configs/android.bisect.blink_perf.cfg
diff --git a/tools/auto_bisect/configs/android.bisect.blink_perf.cfg b/tools/auto_bisect/configs/android.bisect.blink_perf.cfg
new file mode 100644
index 0000000000000000000000000000000000000000..9787acafe02113d3164306fbfe4a12bb664489f8
--- /dev/null
+++ b/tools/auto_bisect/configs/android.bisect.blink_perf.cfg
@@ -0,0 +1,20 @@
+# This config should find the regression of http://crbug.com/423495.
+# It should reproduce a 10+% change with the culprit CL being a blink change.
+# Based on the config used for:
+# http://build.chromium.org/p/tryserver.chromium.perf/builders/android_nexus7_perf_bisect/builds/394
+
+config = {
+  'command': 'tools/perf/run_benchmark -v --browser=android-chrome-shell blink_perf.layout',
+  'good_revision': '297772',
+  'bad_revision': '297779',
+  'metric': 'character_fallback/character_fallback',
+  'repeat_count': '2',
+  'max_time_minutes': '5',
+  'truncate_percent': '25',
+  'bug_id': '423495',
+  'gs_bucket': 'chrome-perf',
+  'builder_host': 'master4.golo.chromium.org',
+  'builder_port': '8341',
+}
+
+# Workaround git try issue, see crbug.com/257689