[WIP]Create a V8 sampler library and tracing controller.

BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/mips.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 if (is_android) {
@@ skipping 603 matching lines @@
 source_set("v8_base") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   sources = [
     # TODO(fmeawad): This needs to be updated to support standalone V8 builds.
     "../base/trace_event/common/trace_event_common.h",
     "include/v8-debug.h",
     "include/v8-experimental.h",
     "include/v8-platform.h",
     "include/v8-profiler.h",
+    "include/v8-sampler.h",
     "include/v8-testing.h",
+    "include/v8-tracing-controller.h",
     "include/v8-util.h",
     "include/v8-version.h",
     "include/v8.h",
     "include/v8config.h",
     "src/accessors.cc",
     "src/accessors.h",
     "src/address-map.cc",
     "src/address-map.h",
     "src/allocation.cc",
     "src/allocation.h",
@@ skipping 690 matching lines @@
     "src/unicode.h",
     "src/unicode-cache-inl.h",
     "src/unicode-cache.h",
     "src/unicode-decoder.cc",
     "src/unicode-decoder.h",
     "src/utils-inl.h",
     "src/utils.cc",
     "src/utils.h",
     "src/v8.cc",
     "src/v8.h",
+    "src/v8-sampler.cc",
+    "src/v8-tracing-controller.cc"
     "src/v8memory.h",
     "src/v8threads.cc",
     "src/v8threads.h",
     "src/version.cc",
     "src/version.h",
     "src/vm-state-inl.h",
     "src/vm-state.h",
     "src/wasm/asm-wasm-builder.cc",
     "src/wasm/asm-wasm-builder.h",
     "src/wasm/ast-decoder.cc",
@@ skipping 647 matching lines @@
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
   configs += [
     ":internal_config",
     ":features",
     ":toolchain",
   ]
 }