Adding a test for measuring memory usage.

tools/perf/perf_tools/memory_benchmark.py

+# Copyright (c) 2012 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.
+from telemetry import page_interaction
+from telemetry import multi_page_benchmark
+
+MEMORY_HISTOGRAMS = [
+    {'name': 'V8.MemoryExternalFragmentationTotal', 'units': 'percent'},
+    {'name': 'V8.MemoryHeapSampleTotalCommitted', 'units': 'kb'},
+    {'name': 'V8.MemoryHeapSampleTotalUsed', 'units': 'kb'}]
+
+class MemoryBenchmark(multi_page_benchmark.MultiPageBenchmark):
+  def __init__(self):
+    super(MemoryBenchmark, self).__init__()
+
+  @staticmethod
+  def GetMemoryHistograms(tab, results):
+    for histogram in MEMORY_HISTOGRAMS:
+      name = histogram['name']
+      data = tab.runtime.Evaluate(
+          'window.domAutomationController.getHistogram("%s")' % name)
+      results.Add(name, histogram['units'], data, data_type='histogram')
+
+  def CustomizeBrowserOptions(self, pages, options):

[nduca, 2012/11/09 19:39:06]

I'd rather you not make this change. If you do the interactions up on
multi_page_benchmark or page_runner you dont have to modify customize
interactions.

[marja, 2012/11/12 12:23:31]

Ok, I moved the interactions to MultiPageBenchmark. But still the test needs to
customize the browser options based on the interactions it will run, so, it
needs the page set to customize the browser options. So I added a
CustomizeBrowserOptionsForPageSet() there. The subclasses don't need to override
it.

+    for page in pages:
+      if hasattr(page, 'stress_memory'):
+        interaction = (
+            page_interaction.FindClassWithName(page.stress_memory['action'])(
+                page.stress_memory))
+        interaction.CustomizeBrowserOptions(options)
+    options.AppendExtraBrowserArg('--dom-automation')
+
+  def MeasurePage(self, page, tab, results):
+    if hasattr(page, 'stress_memory'):

[nduca, 2012/11/09 19:39:06]

This stuff is why you want the page_runner to understand interactions. We'd load
all these other pages only to discover that we didn't want them. :) That'd be
super bad for bot cycle time

[marja, 2012/11/12 12:23:31]

K, I added CanRunForPage to PageTest, and the PageRunner checks it, and doesn't
load pages which the test can't run. (Just having no interactions for the test
doesn't mean that a test can't run, so I needed a separate way to detect
that...)

+      interaction = (
+          page_interaction.FindClassWithName(page.stress_memory['action'])(
+              page.stress_memory))
+      tab.WaitForDocumentReadyStateToBeComplete()
+      interaction.PerformInteraction(page, tab)
+      self.GetMemoryHistograms(tab, results)