Remove carriage returns.

Also add a presubmit so they don't get added to source code.

Change-Id: I6a85c6a934b1068a63646a0dcc0d3a08baa96ced
Reviewed-on: https://skia-review.googlesource.com/57110
Reviewed-by: Ravi Mistry <rmistry@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 83e2d58..c117915 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -222,6 +222,9 @@
   results.extend(
       _CheckChangeHasEol(
           input_api, output_api, source_file_filter=sources))
+  results.extend(
+      input_api.canned_checks.CheckChangeHasNoCR(
+          input_api, output_api, source_file_filter=sources))
   results.extend(_PythonChecks(input_api, output_api))
   results.extend(_IfDefChecks(input_api, output_api))
   results.extend(_CopyrightChecks(input_api, output_api,