Blacklist ReadPixels on GalaxyS4 due to skia:4368.

BUG=skia:4368

Review URL: https://codereview.chromium.org/1366723002
diff --git a/tools/dm_flags.json b/tools/dm_flags.json
index 37366ac..6a05726 100644
--- a/tools/dm_flags.json
+++ b/tools/dm_flags.json
@@ -402,7 +402,8 @@
     "~desk_yahoonews_0", 
     "~imagefiltersclipped", 
     "~scaled_tilemodes_npot", 
-    "~bleed_image"
+    "~bleed_image", 
+    "~ReadPixels"
   ], 
   "Test-Android-GCC-Nexus7-GPU-Tegra3-Arm7-Release": [
     "--config", 
diff --git a/tools/dm_flags.py b/tools/dm_flags.py
index 16ba041..f33889c 100755
--- a/tools/dm_flags.py
+++ b/tools/dm_flags.py
@@ -171,8 +171,8 @@
   if 'GalaxyS4' in bot:  # skia:4079
     match.append('~imagefiltersclipped')
     match.append('~scaled_tilemodes_npot')
-    # skia:4367
-    match.append('~bleed_image')
+    match.append('~bleed_image')  # skia:4367
+    match.append('~ReadPixels')  # skia:4368
 
   if match:
     args.append('--match')