Run correctness tests on ANGLE bots using d3d9 backend

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3584

CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Win-MSVC-ShuttleC-GPU-GTX960-x86_64-Debug-ANGLE-Trybot

Change-Id: Ic70002d13261d22d374f0fd29e2f8dd3c783d552
Reviewed-on: https://skia-review.googlesource.com/3584
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

infra/bots/recipes/swarm_test.expected/Test-Win8-MSVC-ShuttleB-GPU-GTX960-x86_64-Debug-ANGLE.json

@@ -229,6 +229,7 @@
       "tiles_rt-8888",
       "pic-8888",
       "angle_d3d11_es2",
+      "angle_d3d9_es2",
       "--src",
       "tests",
       "gm",

infra/bots/recipes/swarm_test.py

@@ -115,7 +115,7 @@ def dm_flags(bot):
                    ['serialize', 'tiles_rt', 'pic'])
 
   if 'ANGLE' in bot:
-    configs.append('angle_d3d11_es2')
+    configs.extend(['angle_d3d11_es2', 'angle_d3d9_es2'])
 
   # We want to run gpudft on atleast the mali 400
   if 'GalaxyS3' in bot:

tools/flags/SkCommonFlagsConfig.cpp

@@ -61,6 +61,7 @@ static const struct {
     { "debug",           "gpu", "api=debug" },
     { "nullgpu",         "gpu", "api=null" },
     { "angle_d3d11_es2", "gpu", "api=angle_d3d11_es2" },
+    { "angle_d3d9_es2",  "gpu", "api=angle_d3d9_es2" },
     { "angle_gl_es2",    "gpu", "api=angle_gl_es2" },
     { "commandbuffer",   "gpu", "api=commandbuffer" }
 #if SK_MESA