Be explicit about namespace testing to not mix it with blink::testing

third_party/WebKit/Source/platform/scheduler/child/webthread_impl_for_worker_scheduler_unittest.cc

Index: third_party/WebKit/Source/platform/scheduler/child/webthread_impl_for_worker_scheduler_unittest.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/child/webthread_impl_for_worker_scheduler_unittest.cc b/third_party/WebKit/Source/platform/scheduler/child/webthread_impl_for_worker_scheduler_unittest.cc
index 578186687c593bbda7ef1449049124b10be99fae..877bc1964b1dbdd02826479b3e8a79f5f6463fa1 100644
--- a/third_party/WebKit/Source/platform/scheduler/child/webthread_impl_for_worker_scheduler_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/child/webthread_impl_for_worker_scheduler_unittest.cc
@@ -13,10 +13,10 @@
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-using testing::_;
-using testing::AnyOf;
-using testing::ElementsAre;
-using testing::Invoke;
+using ::testing::_;
+using ::testing::AnyOf;
+using ::testing::ElementsAre;
+using ::testing::Invoke;
 
 namespace blink {
 namespace scheduler {
@@ -70,7 +70,7 @@ void ShutdownOnThread(WebThreadImplForWorkerScheduler* thread) {
 
 }  // namespace
 
-class WebThreadImplForWorkerSchedulerTest : public testing::Test {
+class WebThreadImplForWorkerSchedulerTest : public ::testing::Test {
  public:
   WebThreadImplForWorkerSchedulerTest() {}
 
@@ -173,7 +173,8 @@ TEST_F(WebThreadImplForWorkerSchedulerTest, TestTaskObserver) {
   // Sometimes we get an internal scheduler task running before or after
   // TestTask as well. This is not a bug, and we need to make sure the test
   // doesn't fail when that happens.
-  EXPECT_THAT(calls, testing::HasSubstr("willProcessTask run didProcessTask"));
+  EXPECT_THAT(calls,
+              ::testing::HasSubstr("willProcessTask run didProcessTask"));
 }
 
 TEST_F(WebThreadImplForWorkerSchedulerTest, TestShutdown) {