restore LOG_FATAL crash key on windows

chrome/common/child_process_logging_win.cc

Index: chrome/common/child_process_logging_win.cc
diff --git a/chrome/common/child_process_logging_win.cc b/chrome/common/child_process_logging_win.cc
index 3460812edc0551745f9264347d399e93eba0f020..4346af5b00a6cc748e2341934a46dc14a3b57ab2 100644
--- a/chrome/common/child_process_logging_win.cc
+++ b/chrome/common/child_process_logging_win.cc
@@ -8,6 +8,7 @@
 
 #include <memory>
 
+#include "base/auto_reset.h"
 #include "base/debug/crash_logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/common/chrome_constants.h"
@@ -52,11 +53,25 @@ void ClearCrashKeyValueTrampoline(const base::StringPiece& key) {
     (clear_crash_key)(base::UTF8ToWide(key).data());
 }
 
+// Please keep synced with one in crashpad.cc.
+void CrashMessageHandler(const std::string& message) {
+  // In case of an out-of-memory condition, this code could be reentered when
+  // constructing and storing the key. Using a static is not thread-safe, but
+  // if multiple threads are in the process of a fatal crash at the same time,
+  // this should work.
+  static bool guarded = false;
+  if (!guarded) {
+    base::AutoReset<bool> guard(&guarded, true);
+    base::debug::SetCrashKeyValue("LOG_FATAL", message);
+  }
+}
+
 }  // namespace
 
 void Init() {
   base::debug::SetCrashKeyReportingFunctions(&SetCrashKeyValueTrampoline,
                                              &ClearCrashKeyValueTrampoline);
+  logging::SetCrashMessageHandler(CrashMessageHandler);
 
   // This would be handled by BreakpadClient::SetCrashClientIdFromGUID(), but
   // because of the aforementioned issue, crash keys aren't ready yet at the