Add full frame measurement mode for some blink_perf tests

tools/perf/benchmarks/blink_perf.py

Index: tools/perf/benchmarks/blink_perf.py
diff --git a/tools/perf/benchmarks/blink_perf.py b/tools/perf/benchmarks/blink_perf.py
index 20d3a025ebceeb4bfbb020b69684339d4fe674d4..6838b998ad877e163fb7a1c2e3849ce09907a692 100644
--- a/tools/perf/benchmarks/blink_perf.py
+++ b/tools/perf/benchmarks/blink_perf.py
@@ -70,11 +70,19 @@ class _BlinkPerfMeasurement(page_test.PageTest):
   def WillNavigateToPage(self, page, tab):
     page.script_to_evaluate_on_commit = self._blink_perf_js
 
+  # Some blink perf tests require content_shell with window.intenals API.
+  def CustomizeFinderOptions(self, options):

[tonyg, 2014/10/27 19:11:57]

This doesn't seem right. We shouldn't just change the browser that the user is
running against.

If some tests require content shell, then they should fatally exit with an error
message explaining that when they're run against an unsupported browser and the
bots should be changed to pass the desired browser.

But maybe we should talk more about what we're relying on in
--expose-internals-for-testing? It'd be nice to be able to run these tests
against chrome too.

[Xianzhu, 2014/10/27 20:43:28]

We want to let the tests cover the cost of compositing update and paint
invalidation if possible. Now these operations can't be triggered with public
JavaScript API, but only with window.internals.forceCompositingUpdate() API.

Actually the tests can still run in chrome, but the performance results won't
reflect cost of compositing update and paint invalidation.

How about the following:
1. change code to display a warning when the browser_type is not as expected;
2. change build bot code to use content_shell for blink_perf tests.

+    if options.browser_type == 'release':
+      options.browser_type = 'content-shell-release'
+    elif options.browser_type == 'debug':
+      options.browser_type = 'content-shell-debug'
+
   def CustomizeBrowserOptions(self, options):
     options.AppendExtraBrowserArgs([
         '--js-flags=--expose_gc',
         '--enable-experimental-web-platform-features',
-        '--disable-gesture-requirement-for-media-playback'
+        '--disable-gesture-requirement-for-media-playback',
+        '--expose-internals-for-testing'
     ])
 
   def ValidateAndMeasurePage(self, page, tab, results):