Re-enable GPU raster and HW canvas on 10.13.4 and above

The stability issues in 10.13's earlier releases appear to have been
fixed in 10.13.4.

Bug: 773705
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: Ib483847c6b8b8779448b6d47d5ab3cd6a72d2c34
Reviewed-on: https://chromium-review.googlesource.com/1011252Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: ccameron <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550544}

gpu/config/software_rendering_list.json

@@ -1543,7 +1543,7 @@
     },
     {
       "id": 150,
-      "description": "Macs with NVidia GPUs experience rendering issues on High Sierra",
+      "description": "Macs with NVidia GPUs experience rendering issues on High Sierra until 10.13.4",
       "cr_bugs": [773705],
       "os": {
         "type": "macosx",
@@ -1552,6 +1552,17 @@
           "value": "10.13"
         }
       },
+      "exceptions": [
+        {
+          "os": {
+            "type": "macosx",
+            "version": {
+              "op": ">=",
+              "value": "10.13.4"
+            }
+          }
+        }
+      ],
       "vendor_id": "0x10de",
       "multi_gpu_category": "any",
       "features": [