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..82b10a5dd25addb8baa5d495b1117e25300c18ff
--- /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 absolute path, '

[charliea (OOO until 10-5), 2017/05/10 20:59:16]

This doesn't make it quite clear whether you're allowed to pass a single test or
multiple tests? Or a directory?

[charliea (OOO until 10-5), 2017/05/10 20:59:16]

Maybe:

"Path to blink perf tests. Could be an absolute path, a relative path with
respect to your current directory, a relative path with respect to
third_party/WebKit/PerformanceTest"

[nednguyen, 2017/05/10 21:03:02]

Done.

+                            'or relative path (with respect to your current '
+                            'directory or '
+                            '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)