Add unittest to avoid duplicate id in gpu driver bug list

gpu/config/gpu_driver_bug_list_unittest.cc

Index: gpu/config/gpu_driver_bug_list_unittest.cc
diff --git a/gpu/config/gpu_driver_bug_list_unittest.cc b/gpu/config/gpu_driver_bug_list_unittest.cc
index 09612d20ab8a0e9fc28b2ddf7d7b43e50152211a..9a085fd51a4c118b8b53f5702ba430e8183a70d8 100644
--- a/gpu/config/gpu_driver_bug_list_unittest.cc
+++ b/gpu/config/gpu_driver_bug_list_unittest.cc
@@ -207,5 +207,11 @@ TEST_F(GpuDriverBugListTest, NVIDIANumberingScheme) {
   EXPECT_EQ(0u, bugs.count(DISABLE_D3D11));
 }
 
+TEST_F(GpuDriverBugListTest, DuplicateBugIDCheck) {

[Zhenyao Mo, 2016/10/17 17:30:04]

nit: Duplicate -> Duplicated.

[qiankun, 2016/10/18 01:52:56]

Done.

+  std::unique_ptr<GpuDriverBugList> list(GpuDriverBugList::Create());
+  EXPECT_TRUE(list->LoadList(kGpuDriverBugListJson, GpuControlList::kAllOs));
+  EXPECT_FALSE(list->has_duplicate_entry_id());
+}
+
 }  // namespace gpu