replace COMPILE_ASSERT with static_assert in platform/

Source/platform/WebThread.cpp

 // 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.
 
 #include "config.h"
 #include "public/platform/WebThread.h"
 
 #include "wtf/Assertions.h"
 
 #if OS(WIN)
 #include <windows.h>
 #elif OS(POSIX)
 #include <unistd.h>
 #endif
 
 namespace {
 #if OS(WIN)
-COMPILE_ASSERT(sizeof(blink::PlatformThreadId) >= sizeof(DWORD), Size_of_platform_thread_id_is_too_small);
+static_assert(sizeof(blink::PlatformThreadId) >= sizeof(DWORD), "size of platform thread id is too small");
 #elif OS(POSIX)
-COMPILE_ASSERT(sizeof(blink::PlatformThreadId) >= sizeof(pid_t), Size_of_platform_thread_id_is_too_small);
+static_assert(sizeof(blink::PlatformThreadId) >= sizeof(pid_t), "size of platform thread id is too small");
 #else
 #error Unexpected platform
 #endif
 }