Remove unused trace sampling states

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 8923902ad604e17b7f0cb990aed2f5a04ea3c321..bf2528fb626af356c65765743242ccd16b70ac94 100644
--- a/sky/engine/public/platform/Platform.h
+++ b/sky/engine/public/platform/Platform.h
@@ -234,14 +234,6 @@ public:
     // addTraceEvent is expected to be called by the trace event macros.
     virtual const unsigned char* getTraceCategoryEnabledFlag(const char* categoryName) { return 0; }
 
-    typedef long int TraceEventAPIAtomicWord;
-
-    // Get a pointer to a global state of the given thread. An embedder is
-    // expected to update the global state as the state of the embedder changes.
-    // A sampling thread in the Chromium side reads the global state periodically
-    // and reflects the sampling profiled results into about:tracing.
-    virtual TraceEventAPIAtomicWord* getTraceSamplingState(const unsigned bucketName) { return 0; }
-
     typedef uint64_t TraceEventHandle;
 
     // Add a trace event to the platform tracing system. Depending on the actual