Blink Platform: Remove time functions from Platform.

third_party/WebKit/Source/platform/TimerTest.cpp

Index: third_party/WebKit/Source/platform/TimerTest.cpp
diff --git a/third_party/WebKit/Source/platform/TimerTest.cpp b/third_party/WebKit/Source/platform/TimerTest.cpp
index 9bbb0a7149c1d32a8b5a44358e2483730f2bacd4..4284a625be935ceb275490158838a1b5d4dd24c1 100644
--- a/third_party/WebKit/Source/platform/TimerTest.cpp
+++ b/third_party/WebKit/Source/platform/TimerTest.cpp
@@ -280,13 +280,18 @@ class TimerTest : public testing::Test {
 public:
     void SetUp() override
     {
-        WTF::setMonotonicallyIncreasingTimeFunction(currentTime);
+        m_originalTimeFunction = setTimeFunctionsForTesting(currentTime);
 
         m_runTimes.clear();
         gCurrentTimeSecs = 10.0;
         m_startTime = gCurrentTimeSecs;
     }
 
+    void TearDown() override
+    {
+        setTimeFunctionsForTesting(m_originalTimeFunction);
+    }
+
     void countingTask(Timer<TimerTest>*)
     {
         m_runTimes.append(monotonicallyIncreasingTime());
@@ -334,6 +339,7 @@ protected:
 
 private:
     TimerTestPlatform m_platform;
+    TimeFunction m_originalTimeFunction;
 };
 
 TEST_F(TimerTest, StartOneShot_Zero)