[Telemetry] Migrate bitmap.py from bitmaptools.cc to numpy

tools/perf/metrics/speedindex.py

Index: tools/perf/metrics/speedindex.py
diff --git a/tools/perf/metrics/speedindex.py b/tools/perf/metrics/speedindex.py
index 2daff4e5b8d21d1788b40a03d59fe1b9b2cd01b5..389cd7e0c767565ab1fe4c272d7a6ce31b8e0724 100644
--- a/tools/perf/metrics/speedindex.py
+++ b/tools/perf/metrics/speedindex.py
@@ -5,7 +5,8 @@
 import collections
 
 from metrics import Metric
-from telemetry.core import bitmap
+from telemetry.image_processing import image_util
+from telemetry.image_processing import rgba_color
 from telemetry.value import scalar
 
 
@@ -137,15 +138,17 @@ class SpeedIndexImpl(object):
 
 class VideoSpeedIndexImpl(SpeedIndexImpl):
 
-  def __init__(self):
+  def __init__(self, image_util_module=image_util):
+    # Allow image_util to be passed in so we can fake it out for testing.
     super(VideoSpeedIndexImpl, self).__init__()
     self._time_completeness_list = None
+    self._image_util_module = image_util_module
 
   def Start(self, tab):
     assert tab.video_capture_supported
     # Blank out the current page so it doesn't count towards the new page's
     # completeness.
-    tab.Highlight(bitmap.WHITE)
+    tab.Highlight(rgba_color.WHITE)
     # TODO(tonyg): Bitrate is arbitrary here. Experiment with screen capture
     # overhead vs. speed index accuracy and set the bitrate appropriately.
     tab.StartVideoCapture(min_bitrate_mbps=4)
@@ -157,9 +160,9 @@ class VideoSpeedIndexImpl(SpeedIndexImpl):
     # video capture at 4mbps. We should keep this as low as possible with
     # supported video compression settings.
     video_capture = tab.StopVideoCapture()
-    histograms = [(time, bmp.ColorHistogram(ignore_color=bitmap.WHITE,
-                                            tolerance=8))
-                  for time, bmp in video_capture.GetVideoFrameIter()]
+    histograms = [(time, self._image_util_module.GetColorHistogram(
+                       image, ignore_color=rgba_color.WHITE, tolerance=8))
+                  for time, image in video_capture.GetVideoFrameIter()]
 
     start_histogram = histograms[0][1]
     final_histogram = histograms[-1][1]