Add the local blink_perf benchmark that supports running any subdir of WebKit/PerformanceTest

tools/perf/contrib/blink_perf_cmdline/blink_perf_cmdline.py

Index: tools/perf/contrib/blink_perf_cmdline/blink_perf_cmdline.py
diff --git a/tools/perf/contrib/blink_perf_cmdline/blink_perf_cmdline.py b/tools/perf/contrib/blink_perf_cmdline/blink_perf_cmdline.py
new file mode 100644
index 0000000000000000000000000000000000000000..d146e162ee6f330ace66a7475afa52acbd18c6a3
--- /dev/null
+++ b/tools/perf/contrib/blink_perf_cmdline/blink_perf_cmdline.py
@@ -0,0 +1,32 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+import os
+
+from benchmarks import blink_perf
+
+
+# pylint: disable=protected-access
+class BlinkPerfAll(blink_perf._BlinkPerfBenchmark):
+
+  @classmethod
+  def Name(cls):
+    return 'blink_perf'
+
+  @classmethod
+  def AddBenchmarkCommandLineArgs(cls, parser):
+    parser.add_option('--test-path', type='string',
+                      default=blink_perf.BLINK_PERF_BASE_DIR,
+                      help=('Path to blink perf tests. Could be an absolute '
+                            'path, a relative path with respect to your '
+                            'current directory, or a relative path with '
+                            'respect to third_party/WebKit/PerformanceTest/)'))
+
+  def CreateStorySet(self, options):
+    if os.path.exists(options.test_path):
+      path = os.path.abspath(options.test_path)
+    else:
+      path = os.path.join(blink_perf.BLINK_PERF_BASE_DIR, options.test_path)
+    print
+    print 'Running all tests in %s' % path
+    return blink_perf.CreateStorySetFromPath(path, blink_perf.SKIPPED_FILE)