Cleanup interaction creation and add ExecuteJavaScript to action_runner.py

tools/telemetry/telemetry/page/actions/action_runner.py

Index: tools/telemetry/telemetry/page/actions/action_runner.py
diff --git a/tools/telemetry/telemetry/page/actions/action_runner.py b/tools/telemetry/telemetry/page/actions/action_runner.py
index c0847031efed26caabc41ad46939f73427f00a33..cba75b293c5abc7f8143b682f977828fc652f3d8 100644
--- a/tools/telemetry/telemetry/page/actions/action_runner.py
+++ b/tools/telemetry/telemetry/page/actions/action_runner.py
@@ -1,6 +1,8 @@
 # Copyright 2014 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.page.actions.javascript import JavaScriptAction
 from telemetry.page.actions.navigate import NavigateAction
 from telemetry.web_perf import timeline_interaction_record as tir_module
 
@@ -9,33 +11,44 @@ class ActionRunner(object):
   def __init__(self, tab):
     self._tab = tab
 
-  #TODO(nednguyen): remove this when crbug.com/361809 is marked fixed
+  # TODO(nednguyen): remove this (or make private) when
+  # crbug.com/361809 is marked fixed
   def RunAction(self, action):
     if not action.WillWaitAfterRun():
       action.WillRunAction(self._tab)
     action.RunActionAndMaybeWait(self._tab)
 
-  def BeginInteraction(self, logical_name, flags):
-    """ Issues the begin of interaction record.
-        flags contains any flags in web_perf.timeline_interaction_record.
-    """
-    assert self._tab
-    self._tab.ExecuteJavaScript('console.time("%s");' %
-      tir_module.TimelineInteractionRecord.GetJavascriptMarker(logical_name,
-                                                               flags))
-
-  def EndInteraction(self, logical_name, flags):
-    """ Issues the begin of interaction record.
-        flags contains any flags in web_perf.timeline_interaction_record.
+  def BeginInteraction(self, label, is_smooth=False, is_responsive=False):
+    """Marks the beginning of an interaction record.
+
+    An interaction record is a labeled time period containing
+    interaction that developers care about. Each set of metrics
+    specified in flags will be calculated for this time period.. The
+    End() method in the returned object must be called once to mark
+    the end of the timeline.
+
+    Args:
+      label: A label for this particular interaction. This can be any
+          user-defined string, but must not contain '/'.
+      is_smooth: Whether to check for smoothness metrics for this interaction.
+      is_responsive: Whether to check for responsiveness metrics for
+          this interaction.
     """
-    assert self._tab
-    self._tab.ExecuteJavaScript('console.timeEnd("%s");' %
-      tir_module.TimelineInteractionRecord.GetJavascriptMarker(logical_name,
-                                                               flags))
+    flags = []
+    if is_smooth:
+      flags.append(tir_module.IS_SMOOTH)
+    if is_responsive:
+      flags.append(tir_module.IS_RESPONSIVE)
+
+    interaction = Interaction(self._tab, label, flags)
+    interaction.Begin()
+    return interaction
 
   def NavigateToPage(self, page, timeout_seconds=None):
-    """ Navigate to page.
-        page is an instance of page.Page
+    """ Navigate to the given page.
+
+    Args:
+      page: page is an instance of page.Page
     """
     if page.is_file:
       target_side_url = self._tab.browser.http_server.UrlOf(page.file_path_url)
@@ -47,3 +60,39 @@ class ActionRunner(object):
     if timeout_seconds:
       attributes['timeout_seconds'] = timeout_seconds
     self.RunAction(NavigateAction(attributes))
+
+  def ExecuteJavaScript(self, js_expression):
+    """Executes a given JavaScript expression.
+
+    Example: runner.ExecuteJavaScript('var foo = 1;');
+
+    Args:
+      js_expression: The expression to execute (provided as string).
+    """
+    self.RunAction(JavaScriptAction({'expression': js_expression}))
+
+
+class Interaction(object):
+  def __init__(self, action_runner, label, flags):
+    assert action_runner
+    assert label
+    assert isinstance(flags, list)
+
+    self._action_runner = action_runner
+    self._label = label
+    self._flags = flags
+    self._started = False
+
+  def Begin(self):
+    assert not self._started
+    self._started = True
+    self._action_runner.ExecuteJavaScript('console.time("%s");' %
+        tir_module.TimelineInteractionRecord.GetJavaScriptMarker(
+            self._label, self._flags))
+
+  def End(self):
+    assert self._started
+    self._started = False
+    self._action_runner.ExecuteJavaScript('console.timeEnd("%s");' %
+        tir_module.TimelineInteractionRecord.GetJavaScriptMarker(
+            self._label, self._flags))