Fix for 300ms scroll lag on 2013 Mac Pros once idle for 10seconds

gpu/config/gpu_driver_bug_list_unittest.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "gpu/config/gpu_control_list_jsons.h"
 #include "gpu/config/gpu_driver_bug_list.h"
 #include "gpu/config/gpu_driver_bug_workaround_type.h"
@@ skipping 186 matching lines @@
 
   bugs = list->MakeDecision(GpuControlList::kOsWin, "7.0", gpu_info);
   EXPECT_EQ(1u, bugs.count(DISABLE_D3D11));
 
   // test a higher driver version number
   gpu_info.driver_version = "9.18.13.2723";
   bugs = list->MakeDecision(GpuControlList::kOsWin, "7.0", gpu_info);
   EXPECT_EQ(0u, bugs.count(DISABLE_D3D11));
 }
 
+// Test that having two discrete graphics cards on Mac will not try to switch
+// between them.
+TEST_F(GpuDriverBugListTest, DualDiscreteGPUMac) {
+  scoped_ptr<GpuDriverBugList> list(GpuDriverBugList::Create());
+  std::string json;
+  EXPECT_TRUE(list->LoadList(kGpuDriverBugListJson, GpuControlList::kAllOs));
+
+  // Just a single (AMD) card - nothing should be forced.
+  GPUInfo gpu_info;
+  gpu_info.gpu.vendor_id = 0x1002;
+  std::set<int> bugs =
+      list->MakeDecision(GpuControlList::kOsMacosx, "10.9", gpu_info);
+  EXPECT_EQ(0u, bugs.count(FORCE_DISCRETE_GPU));
+
+  // Add an integrated (intel) card. This will always be secondary.
+  gpu_info.secondary_gpus.resize(1);
+  gpu_info.secondary_gpus.back().vendor_id = 0x8086;
+  bugs = list->MakeDecision(GpuControlList::kOsMacosx, "10.9", gpu_info);
+  EXPECT_EQ(0u, bugs.count(FORCE_DISCRETE_GPU));
+
+  // Add a secondary discrete GPU. Should force discrete.
+  gpu_info.secondary_gpus.back().vendor_id = 0x1002;
+  bugs = list->MakeDecision(GpuControlList::kOsMacosx, "10.9", gpu_info);
+  EXPECT_EQ(1u, bugs.count(FORCE_DISCRETE_GPU));
+
+  // No effect on other platforms.
+  bugs = list->MakeDecision(GpuControlList::kOsWin, "7.0", gpu_info);
+  EXPECT_EQ(0u, bugs.count(FORCE_DISCRETE_GPU));
+}
+
 }  // namespace gpu
-