Optionally run RAW images serially

tools/dm_flags.py

Index: tools/dm_flags.py
diff --git a/tools/dm_flags.py b/tools/dm_flags.py
index e9d5d64bcea9b9a80800ea0a55bbdaf647dfd954..5542e4fb4bb882c4428e63fb66ac5ca97e2f8afc 100755
--- a/tools/dm_flags.py
+++ b/tools/dm_flags.py
@@ -155,14 +155,10 @@ def get_args(bot):
     blacklist.extend([   '2ndpic-8888', 'gm', '_', test])
     blacklist.extend(['serialize-8888', 'gm', '_', test])
 
+  # Extensions for RAW images
   r = ["arw", "cr2", "dng", "nef", "nrw", "orf", "raf", "rw2", "pef", "srw",
        "ARW", "CR2", "DNG", "NEF", "NRW", "ORF", "RAF", "RW2", "PEF", "SRW"]
 
-  # NexusPlayer runs out of memory running RAW codec tests
-  if 'NexusPlayer' in bot:
-    for raw_ext in r:
-      blacklist.extend(('_ image _ .%s' % raw_ext).split(' '))
-
   # skbug.com/4888
   # Blacklist RAW images on GPU tests until we can resolve failures
   if 'GPU' in bot:
@@ -206,6 +202,11 @@ def get_args(bot):
     args.append('--match')
     args.extend(match)
 
+  # These bots run out of memory running RAW codec tests. Do not run them in
+  # parallel
+  if 'NexusPlayer' in bot or 'Nexus5' in bot or 'Nexus9' in bot:
+    args.append('--noRAW_threading')
+
   return args
 cov_end = lineno()   # Don't care about code coverage past here.