Remove TRACE_EVENT indirection through blink::Platform

sky/engine/platform/BUILD.gn

Index: sky/engine/platform/BUILD.gn
diff --git a/sky/engine/platform/BUILD.gn b/sky/engine/platform/BUILD.gn
index 7a607831d11929deedcfef34f32df24339d2905a..f9be7a9b0a56278468d5f47a0adac6ff9912b559 100644
--- a/sky/engine/platform/BUILD.gn
+++ b/sky/engine/platform/BUILD.gn
@@ -116,15 +116,12 @@ source_set("platform") {
     "Decimal.cpp",
     "Decimal.h",
     "EventDispatchForbiddenScope.h",
-    "EventTracer.cpp",
-    "EventTracer.h",
     "exported/linux/WebFontInfo.cpp",
     "exported/linux/WebFontRenderStyle.cpp",
     "exported/Platform.cpp",
     "exported/ServiceProvider.cpp",
     "exported/WebArrayBuffer.cpp",
     "exported/WebCommon.cpp",
-    "exported/WebConvertableToTraceFormat.cpp",
     "exported/WebCString.cpp",
     "exported/WebCursorInfo.cpp",
     "exported/WebData.cpp",
@@ -539,8 +536,6 @@ source_set("platform") {
     "ThreadTimers.h",
     "Timer.cpp",
     "Timer.h",
-    "TracedValue.cpp",
-    "TracedValue.h",
     "TraceEvent.h",
     "transforms/AffineTransform.cpp",
     "transforms/AffineTransform.h",
@@ -667,7 +662,6 @@ test("platform_unittests") {
     "SharedBufferTest.cpp",
     "TestingPlatformSupport.cpp",
     "TestingPlatformSupport.h",
-    "TracedValueTest.cpp",
     "animation/TimingFunctionTest.cpp",
     "animation/UnitBezierTest.cpp",
     "clipboard/ClipboardUtilitiesTest.cpp",