[Tracing] Make TracingCategoryObserver v8 internal.

src/v8.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/assembler.h"
 #include "src/base/once.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
 #include "src/crankshaft/lithium-allocator.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/elements.h"
 #include "src/frames.h"
 #include "src/isolate.h"
 #include "src/libsampler/sampler.h"
 #include "src/objects.h"
 #include "src/profiler/heap-profiler.h"
 #include "src/runtime-profiler.h"
 #include "src/snapshot/natives.h"
 #include "src/snapshot/snapshot.h"
-
+#include "src/tracing/tracing-category-observer.h"
 
 namespace v8 {
 namespace internal {
 
 V8_DECLARE_ONCE(init_once);
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
 V8_DECLARE_ONCE(init_natives_once);
 V8_DECLARE_ONCE(init_snapshot_once);
 #endif
@@ skipping 53 matching lines @@
 
 void V8::InitializeOncePerProcess() {
   base::CallOnce(&init_once, &InitializeOncePerProcessImpl);
 }
 
 
 void V8::InitializePlatform(v8::Platform* platform) {
   CHECK(!platform_);
   CHECK(platform);
   platform_ = platform;
+  v8::tracing::TracingCategoryObserver::SetUp();
 }
 
 
 void V8::ShutdownPlatform() {
   CHECK(platform_);
+  v8::tracing::TracingCategoryObserver::TearDown();
   platform_ = NULL;
 }
 
 
 v8::Platform* V8::GetCurrentPlatform() {
   DCHECK(platform_);
   return platform_;
 }
 
 
@@ skipping 11 matching lines @@
 
 void V8::SetSnapshotBlob(StartupData* snapshot_blob) {
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
   base::CallOnce(&init_snapshot_once, &SetSnapshotFromFile, snapshot_blob);
 #else
   CHECK(false);
 #endif
 }
 }  // namespace internal
 }  // namespace v8