Gpu tests: Allow zero device ID on in Mac GPUTestBotConfig::IsValid

The ARM DTK does not specify a PCI device ID for the GPU. Do not fail
in this configuration.

Bug: 1121672
Change-Id: Idf2d35ed7ff15d43c300203160cec6a74a31d5ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2427567Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: ccameron <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810321}

gpu/config/gpu_test_config.cc

@@ -239,8 +239,12 @@ bool GPUTestBotConfig::IsValid() const {
   }
   if (gpu_vendor().size() != 1 || gpu_vendor()[0] == 0)
     return false;
-  if (gpu_device_id() == 0)
-    return false;
+  if (!(os() & gpu::GPUTestConfig::kOsMac)) {
+    // ARM-based Mac GPUs do not have valid PCI device IDs.
+    // https://crbug.com/1110421
+    if (gpu_device_id() == 0)
+      return false;
+  }
   switch (build_type()) {
     case kBuildTypeRelease:
     case kBuildTypeDebug:

gpu/config/gpu_test_config_unittest.cc

@@ -66,8 +66,13 @@ TEST_F(GPUTestConfigTest, IsValid) {
     config.AddGPUVendor(0x10de);
     EXPECT_TRUE(config.IsValid());
 
+    // Device ID of 0 is valid only on macOS.
     config.set_gpu_device_id(0);
+    config.set_os(GPUTestConfig::kOsMacBigSur);
+    EXPECT_TRUE(config.IsValid());
+    config.set_os(GPUTestConfig::kOsWin7);
     EXPECT_FALSE(config.IsValid());
+
     config.set_gpu_device_id(0x0640);
     EXPECT_TRUE(config.IsValid());