Fix missing StackFrameDepth constructor

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

Index: third_party/WebKit/Source/platform/heap/StackFrameDepth.h
diff --git a/third_party/WebKit/Source/platform/heap/StackFrameDepth.h b/third_party/WebKit/Source/platform/heap/StackFrameDepth.h
index 4ae894c12c8b14c9a2eac198bcd27efe44dc4c01..94b532c818c50ad3cab12830b810d553c9b26930 100644
--- a/third_party/WebKit/Source/platform/heap/StackFrameDepth.h
+++ b/third_party/WebKit/Source/platform/heap/StackFrameDepth.h
@@ -22,6 +22,7 @@ namespace blink {
 class PLATFORM_EXPORT StackFrameDepth final {
     DISALLOW_NEW();
 public:
+    StackFrameDepth(): m_stackFrameLimit(kMinimumStackLimit) {}
     bool isSafeToRecurse()
     {
         // Asssume that the stack grows towards lower addresses, which