Add ability to specify a different base dir path to record_wpr

tools/telemetry/telemetry/page/record_wpr.py

Index: tools/telemetry/telemetry/page/record_wpr.py
diff --git a/tools/telemetry/telemetry/page/record_wpr.py b/tools/telemetry/telemetry/page/record_wpr.py
index 97919e0157d29f9041666dd186579bbcf71fe6e4..f1f811b76b3788aa34f4d5ef2b0a44e64f2d6010 100644
--- a/tools/telemetry/telemetry/page/record_wpr.py
+++ b/tools/telemetry/telemetry/page/record_wpr.py
@@ -123,7 +123,12 @@ class WprRecorder(object):
     self._AddCommandLineArgs()
     self._ParseArgs(args)
     self._ProcessCommandLineArgs()
-    self._page_set = self._GetPageSet(base_dir, target)
+
+    if self._options.page_set_base_dir:
+      page_set_base_dir = self._options.page_set_base_dir
+    else:
+      page_set_base_dir = base_dir
+    self._page_set = self._GetPageSet(page_set_base_dir, target)
 
   @property
   def options(self):
@@ -144,6 +149,8 @@ class WprRecorder(object):
     return results_options.CreateResults(benchmark_metadata, self._options)
 
   def _AddCommandLineArgs(self):
+    self._parser.add_option('--page-set-base-dir', action='store',
+                            type='string')
     page_runner.AddCommandLineArgs(self._parser)
     if self._benchmark is not None:
       self._benchmark.AddCommandLineArgs(self._parser)