[telemetry] Add support for dispatching key events

telemetry/telemetry/internal/actions/action_runner.py

Index: telemetry/telemetry/internal/actions/action_runner.py
diff --git a/telemetry/telemetry/internal/actions/action_runner.py b/telemetry/telemetry/internal/actions/action_runner.py
index 19dc78ec1782fc15c6f2a0e5d9c124e66b983a61..ebb61f7c5d7caeb765f62b59c5d31a01717aa33f 100644
--- a/telemetry/telemetry/internal/actions/action_runner.py
+++ b/telemetry/telemetry/internal/actions/action_runner.py
@@ -8,6 +8,7 @@ import urlparse
 
 from telemetry.internal.actions.drag import DragAction
 from telemetry.internal.actions.javascript_click import ClickElementAction
+from telemetry.internal.actions.key_event import KeyPressAction
 from telemetry.internal.actions.load_media import LoadMediaAction
 from telemetry.internal.actions.loop import LoopAction
 from telemetry.internal.actions.mouse_click import MouseClickAction
@@ -567,6 +568,31 @@ class ActionRunner(object):
         direction=direction, distance=distance,
         speed_in_pixels_per_second=speed_in_pixels_per_second))
 
+  def PressKey(self, key, repeat_count=1, repeat_delay_ms=100, timeout=60):
+    """Perform a key press.
+
+    Args:
+      key: DOM value of the pressed key (e.g. 'PageDown', see
+          https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/key).
+      repeat_count: How many times the key should be pressed.
+      repeat_delay_ms: Delay after each keypress (including the last one) in
+          milliseconds.
+    """
+    for _ in xrange(repeat_count):
+      self._RunAction(KeyPressAction(key, timeout=timeout))
+      self.Wait(repeat_delay_ms / 1000.0)
+
+  def EnterText(self, text, character_delay_ms=100, timeout=60):
+    """Enter text by performing key presses.
+
+    Args:
+      text: The text to enter.
+      character_delay_ms: Delay after each keypress (including the last one) in
+          milliseconds.
+    """
+    for c in text:
+      self.PressKey(c, repeat_delay_ms=character_delay_ms, timeout=timeout)
+
   def LoadMedia(self, selector=None, event_timeout_in_seconds=0,
                 event_to_await='canplaythrough'):
     """Invokes load() on media elements and awaits an event.