Cleanup unused #includes and declarations in PlatformImpl

sky/engine/public/platform/Platform.h

Index: sky/engine/public/platform/Platform.h
diff --git a/sky/engine/public/platform/Platform.h b/sky/engine/public/platform/Platform.h
index 8d3ac0d24bf0797bbb8841b4033d3b8f2e838126..e39689508c05dcec27e1f0b1bdf822ed90e2365e 100644
--- a/sky/engine/public/platform/Platform.h
+++ b/sky/engine/public/platform/Platform.h
@@ -189,20 +189,6 @@ public:
     // Returns a value such as "en-US".
     virtual WebString defaultLocale() { return WebString(); }
 
-    // Wall clock time in seconds since the epoch.
-    virtual double currentTime() { return 0; }
-
-    // Monotonically increasing time in seconds from an arbitrary fixed point in the past.
-    // This function is expected to return at least millisecond-precision values. For this reason,
-    // it is recommended that the fixed point be no further in the past than the epoch.
-    virtual double monotonicallyIncreasingTime() { return 0; }
-
-    // Delayed work is driven by a shared timer.
-    typedef void (*SharedTimerFunction)();
-    virtual void setSharedTimerFiredFunction(SharedTimerFunction timerFunction) { }
-    virtual void setSharedTimerFireInterval(double) { }
-    virtual void stopSharedTimer() { }
-
     virtual base::SingleThreadTaskRunner* mainThreadTaskRunner() { return 0; }