If marking system stack is unknown, be more forgiving about stack depths.

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 24 matching lines @@
     static void disableStackLimit()
     {
         s_stackFrameLimit = 0;
 #if ENABLE(ASSERT)
         s_isEnabled = false;
 #endif
     }
 
 #if ENABLE(ASSERT)
     inline static bool isEnabled() { return s_isEnabled; }
+    inline static bool isAcceptableStackUse()
+    {
+        // ASan adds extra stack usage leading to too noisy asserts.
+#if defined(ADDRESS_SANITIZER)
+        return true;
+#else
+        // If a conservative fallback stack size is in effect, use
+        // a larger stack limit so as to avoid false positives.
+        return !s_isEnabled || isSafeToRecurse() || (s_isUsingFallbackStackSize && (s_stackFrameLimit - currentStackFrame()) < 3 * kSafeStackFrameSize);

[haraken, 2016/02/04 01:31:36]

Nit: Slightly clearer:

if (s_isUsingFallbackStackSize)
  return ...;
return ...;

[sof, 2016/02/04 09:54:32]

Done.

+#endif
+    }
 #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)
@@ skipping 14 matching lines @@
 #endif
 
 private:
     // The maximum depth of eager, unrolled trace() calls that is
     // considered safe and allowed.
     static const int kSafeStackFrameSize = 32 * 1024;
 
     static uintptr_t s_stackFrameLimit;
 #if ENABLE(ASSERT)
     static bool s_isEnabled;
+    static bool s_isUsingFallbackStackSize;
 #endif
 };
 
 class StackFrameDepthScope {
     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(StackFrameDepthScope);
 public:
     StackFrameDepthScope()
     {
         StackFrameDepth::enableStackLimit();
         ASSERT(StackFrameDepth::isSafeToRecurse());
     }
 
     ~StackFrameDepthScope()
     {
         StackFrameDepth::disableStackLimit();
     }
 };
 
 } // namespace blink
 
 #endif // StackFrameDepth_h