Fast path for ThreadSpecific for main thread on TLS-slow platforms

third_party/WebKit/Source/platform/heap/StackFrameDepth.h

 // Copyright 2015 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.
 
 #ifndef StackFrameDepth_h
 #define StackFrameDepth_h
 
 #include "platform/PlatformExport.h"
 #include "wtf/Allocator.h"
 #include "wtf/Assertions.h"
@@ skipping 28 matching lines @@
   bool isEnabled() { return m_stackFrameLimit != kMinimumStackLimit; }
   bool isAcceptableStackUse() {
 #if defined(ADDRESS_SANITIZER)
     // ASan adds extra stack usage leading to too noisy asserts.
     return true;
 #else
     return !isEnabled() || isSafeToRecurse();
 #endif
   }
 
-  static size_t getUnderestimatedStackSize();
-  static void* getStackStart();
-
 #if COMPILER(MSVC)
 // Ignore C4172: returning address of local variable or temporary: dummy. This
 // warning suppression has to go outside of the function to take effect.
 #pragma warning(push)
 #pragma warning(disable : 4172)
 #endif
   static uintptr_t currentStackFrame(const char* dummy = nullptr) {
 #if COMPILER(GCC)
     return reinterpret_cast<uintptr_t>(__builtin_frame_address(0));
 #elif COMPILER(MSVC)
@@ skipping 37 matching lines @@
 
   ~StackFrameDepthScope() { m_depth->disableStackLimit(); }
 
  private:
   StackFrameDepth* m_depth;
 };
 
 }  // namespace blink
 
 #endif  // StackFrameDepth_h