[tools/perf] Prepare V8DetachedContextAgeInGCTests for JS API migration

tools/perf/measurements/v8_detached_context_age_in_gc_unittest.py

Index: tools/perf/measurements/v8_detached_context_age_in_gc_unittest.py
diff --git a/tools/perf/measurements/v8_detached_context_age_in_gc_unittest.py b/tools/perf/measurements/v8_detached_context_age_in_gc_unittest.py
index 42e53305d8f8c34f9acd524590e334ecfbbfa5dc..215edaa346eed277f95dc59f2ef56371ab92929f 100644
--- a/tools/perf/measurements/v8_detached_context_age_in_gc_unittest.py
+++ b/tools/perf/measurements/v8_detached_context_age_in_gc_unittest.py
@@ -27,12 +27,17 @@ class FakeTab(object):
     self.histograms = histograms
     self.current_histogram_index = 0
 
-  def EvaluateJavaScript(self, script):
-    if 'V8.DetachedContextAgeInGC' in script:
+  def EvaluateJavaScript(self, script, **kwargs):
+    histogram_name = 'V8.DetachedContextAgeInGC'
+    if kwargs.get('name') == histogram_name or histogram_name in script:

[perezju, 2017/02/14 11:42:04]

Tweaked to work both before and after applying the change in:
https://codereview.chromium.org/2687773003/diff/40001/telemetry/telemetry/val...

       self.current_histogram_index += 1
       return self.histograms[self.current_histogram_index - 1]
     return '{}'
 
+  # TODO(catapult:3028): Remove after migration to new JS API completed.
+  def EvaluateJavaScript2(self, script, **kwargs):
+    return self.EvaluateJavaScript(script, **kwargs)
+
   def CollectGarbage(self):
     pass