[Telemetry] Add support for capturing V8 object stats to Telemetry.

tools/perf/measurements/page_cycler.py

Index: tools/perf/measurements/page_cycler.py
diff --git a/tools/perf/measurements/page_cycler.py b/tools/perf/measurements/page_cycler.py
index e373eeab72694b39f1f202a54aedcf6e2842739e..5d28a2a44977be939d08e6af57ac2c89ad6a92bc 100644
--- a/tools/perf/measurements/page_cycler.py
+++ b/tools/perf/measurements/page_cycler.py
@@ -20,6 +20,7 @@ import sys
 
 from metrics import io
 from metrics import memory
+from metrics import v8_object_stats
 from telemetry.core import util
 from telemetry.page import page_measurement
 
@@ -31,7 +32,11 @@ class PageCycler(page_measurement.PageMeasurement):
                            'page_cycler.js'), 'r') as f:
       self._page_cycler_js = f.read()
 
+    self._record_v8_object_stats = False
+
     self._memory_metric = None
+    self._v8_object_stats_metric = None
+
 
   def AddCommandLineOptions(self, parser):
     # The page cyclers should default to 10 iterations. In order to change the
@@ -42,9 +47,15 @@ class PageCycler(page_measurement.PageMeasurement):
     parser.remove_option('--pageset-repeat')
     parser.add_option(pageset_repeat_option)
 
+    parser.add_option('--v8-object-stats',
+        action='store_true',
+        help='Enable detailed V8 object statistics.')
+
   def DidStartBrowser(self, browser):
     """Initialize metrics once right after the browser has been launched."""
     self._memory_metric = memory.MemoryMetric(browser)
+    if self._record_v8_object_stats:
+      self._v8_object_stats_metric = v8_object_stats.V8ObjectStatsMetric()
 
   def DidStartHTTPServer(self, tab):
     # Avoid paying for a cross-renderer navigation on the first page on legacy
@@ -56,11 +67,21 @@ class PageCycler(page_measurement.PageMeasurement):
 
   def DidNavigateToPage(self, page, tab):
     self._memory_metric.Start(page, tab)
+    if self._record_v8_object_stats:
+      self._v8_object_stats_metric.Start(page, tab)
 
   def CustomizeBrowserOptions(self, options):
-    memory.MemoryMetric.CustomizeBrowserOptions(options)
-    io.IOMetric.CustomizeBrowserOptions(options)
+    options.AppendExtraBrowserArg('--enable-stats-collection-bindings')
     options.AppendExtraBrowserArg('--js-flags=--expose_gc')
+    options.AppendExtraBrowserArg('--no-sandbox')
+
+    # Old commandline flags used for reference builds.
+    options.AppendExtraBrowserArg('--dom-automation')
+
+    # Add custom options required by metrics
+    if options.v8_object_stats:
+      self._record_v8_object_stats = True
+      v8_object_stats.V8ObjectStatsMetric.CustomizeBrowserOptions(options)
 
     # Temporarily disable typical_25 page set on mac.
     if sys.platform == 'darwin' and sys.argv[-1].endswith('/typical_25.json'):
@@ -77,6 +98,9 @@ class PageCycler(page_measurement.PageMeasurement):
 
     self._memory_metric.Stop(page, tab)
     self._memory_metric.AddResults(tab, results)
+    if self._record_v8_object_stats:
+      self._v8_object_stats_metric.Stop(page, tab)
+      self._v8_object_stats_metric.AddResults(tab, results)
 
   def DidRunTest(self, tab, results):
     self._memory_metric.AddSummaryResults(results)