WTF: Initialize main-thread stack estimates when WTF starts up.

third_party/WebKit/Source/wtf/WTF.cpp

Index: third_party/WebKit/Source/wtf/WTF.cpp
diff --git a/third_party/WebKit/Source/wtf/WTF.cpp b/third_party/WebKit/Source/wtf/WTF.cpp
index f6d29b5695cc606b5626c440d4990cd0d8a07532..201efc2747ad2825be7a20eb30bc19c149b53d48 100644
--- a/third_party/WebKit/Source/wtf/WTF.cpp
+++ b/third_party/WebKit/Source/wtf/WTF.cpp
@@ -32,6 +32,8 @@
 
 #include "wtf/Assertions.h"
 #include "wtf/Functional.h"
+#include "wtf/StackUtil.h"
+#include "wtf/ThreadSpecific.h"
 #include "wtf/Threading.h"
 #include "wtf/allocator/Partitions.h"
 #include "wtf/text/AtomicString.h"
@@ -63,10 +65,13 @@ void initialize(void (*callOnMainThreadFunction)(MainThreadFunction, void*)) {
   // Make that explicit here.
   RELEASE_ASSERT(!s_initialized);
   s_initialized = true;
+  initializeCurrentThread();

[haraken, 2017/03/06 01:44:03]

Given that only the main thread calls this, shall we rename it to
initializeMainThread?

[jbroman, 2017/03/06 16:14:03]

It only initializes the one aspect of the main thread. Namely, it initializes
the code necessary for WTF::currentThread to work. (Really, I mean that it's
initializing the "currentThread" function, not that it's initializing the thread
itself.)

I'm open to a better name. I will, at least, add a comment at the function
declaration.

+  s_mainThreadIdentifier = currentThread();
+
   initializeThreading();
 
   s_callOnMainThreadFunction = callOnMainThreadFunction;
-  s_mainThreadIdentifier = currentThread();
+  internal::initializeMainThreadStackEstimate();
   AtomicString::init();
   StringStatics::init();
 }