Add new multipage_skpicture_printer benchmark and measurement

tools/perf/measurements/multipage_skpicture_printer_unittest.py

-# Copyright 2014 The Chromium Authors. All rights reserved.
+# Copyright 2016 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 shutil
 import tempfile
 
 from telemetry import decorators
 from telemetry.testing import options_for_unittests
 from telemetry.testing import page_test_test_case
 
-from measurements import skpicture_printer
+from measurements import multipage_skpicture_printer
 
 
-class SkpicturePrinterUnitTest(page_test_test_case.PageTestTestCase):
+class MultipageSkpicturePrinterUnitTest(page_test_test_case.PageTestTestCase):
 
   def setUp(self):
     self._options = options_for_unittests.GetCopy()
-    self._skp_outdir = tempfile.mkdtemp('_skp_test')
+    self._mskp_outdir = tempfile.mkdtemp('_mskp_test')
 
   def tearDown(self):
-    shutil.rmtree(self._skp_outdir)
+    shutil.rmtree(self._mskp_outdir)
 
   @decorators.Disabled('android')
   def testSkpicturePrinter(self):
     ps = self.CreateStorySetFromFileInUnittestDataDir('blank.html')
-    measurement = skpicture_printer.SkpicturePrinter(self._skp_outdir)
+    measurement = multipage_skpicture_printer.MultipageSkpicturePrinter(
+        self._mskp_outdir)
     results = self.RunMeasurement(measurement, ps, options=self._options)
 
     # Picture printing is not supported on all platforms.
     if results.failures:
       assert 'not supported' in results.failures[0].exc_info[1].message
       return
-
-    saved_picture_count = results.FindAllPageSpecificValuesNamed(
-        'saved_picture_count')
-    self.assertEquals(len(saved_picture_count), 1)
-    self.assertGreater(saved_picture_count[0].GetRepresentativeNumber(), 0)