Fix GPUTestConfigTest.LoadCurrentConfig on macOS Sierra.

gpu/config/gpu_test_expectations_parser.cc

Index: gpu/config/gpu_test_expectations_parser.cc
diff --git a/gpu/config/gpu_test_expectations_parser.cc b/gpu/config/gpu_test_expectations_parser.cc
index 2ae972b29d6b0d0c34b8db8ececf0d88896dae60..6c4f797f5d61785d77aec5ec64c524019770d1f6 100644
--- a/gpu/config/gpu_test_expectations_parser.cc
+++ b/gpu/config/gpu_test_expectations_parser.cc
@@ -43,6 +43,7 @@ enum Token {
   kConfigMacMavericks,
   kConfigMacYosemite,
   kConfigMacElCapitan,
+  kConfigMacSierra,
   kConfigMac,
   kConfigLinux,
   kConfigChromeOS,
@@ -97,6 +98,7 @@ const TokenInfo kTokenData[] = {
     {"mavericks", GPUTestConfig::kOsMacMavericks},
     {"yosemite", GPUTestConfig::kOsMacYosemite},
     {"elcapitan", GPUTestConfig::kOsMacElCapitan},
+    {"sierra", GPUTestConfig::kOsMacSierra},
     {"mac", GPUTestConfig::kOsMac},
     {"linux", GPUTestConfig::kOsLinux},
     {"chromeos", GPUTestConfig::kOsChromeOS},
@@ -259,6 +261,7 @@ bool GPUTestExpectationsParser::ParseConfig(
       case kConfigMacMavericks:
       case kConfigMacYosemite:
       case kConfigMacElCapitan:
+      case kConfigMacSierra:
       case kConfigMac:
       case kConfigLinux:
       case kConfigChromeOS:
@@ -318,6 +321,7 @@ bool GPUTestExpectationsParser::ParseLine(
       case kConfigMacMavericks:
       case kConfigMacYosemite:
       case kConfigMacElCapitan:
+      case kConfigMacSierra:
       case kConfigMac:
       case kConfigLinux:
       case kConfigChromeOS:
@@ -440,6 +444,7 @@ bool GPUTestExpectationsParser::UpdateTestConfig(GPUTestConfig* config,
     case kConfigMacMavericks:
     case kConfigMacYosemite:
     case kConfigMacElCapitan:
+    case kConfigMacSierra:
     case kConfigMac:
     case kConfigLinux:
     case kConfigChromeOS: