restore LOG_FATAL crash key on windows

base/logging.cc

Index: base/logging.cc
diff --git a/base/logging.cc b/base/logging.cc
index 0771b47c182e5c18c868f1124a0784bf411d74a9..dd812c1911d77e0344bd609345bac671cda17ed3 100644
--- a/base/logging.cc
+++ b/base/logging.cc
@@ -53,9 +53,11 @@ typedef pthread_mutex_t* MutexHandle;
 #include <ostream>
 #include <string>
 
+#include "base/auto_reset.h"
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/debug/alias.h"
+#include "base/debug/crash_logging.h"
 #include "base/debug/debugger.h"
 #include "base/debug/stack_trace.h"
 #include "base/posix/eintr_wrapper.h"
@@ -126,6 +128,27 @@ LogAssertHandlerFunction log_assert_handler = nullptr;
 // A log message handler that gets notified of every log message we process.
 LogMessageHandlerFunction log_message_handler = nullptr;
 
+void SetLogFatalCrashKey(size_t message_start,
+                         const std::string& string) {
+// Nacl targets miss base/debug/crash_logging.cc.

[scottmg, 2016/10/05 22:06:21]

nit; "NaCl targets do not have ..."

[rkuksin, 2016/10/06 08:50:33]

Done.

+#if !defined(NACL_TC_REV)

[scottmg, 2016/10/05 22:06:21]

OS_NACL.

[rkuksin, 2016/10/06 08:50:33]

Done.

+  // 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) {
+    return;
+  }
+  base::AutoReset<bool> guard(&guarded, true);
+
+  CHECK_LE(message_start, string.size());
+  std::string message = base::StringPrintf("%s",
+                                           string.c_str() + message_start);
+  base::debug::SetCrashKeyValue("LOG_FATAL", message);

[scottmg, 2016/10/05 22:06:21]

This takes a StringPiece so no need for the Sprintfing? In fact, I would just
inline

#if !defined(OS_NACL)
if (severity_ == LOG_FATAL)
  base::debug::SetCrashKeyValue("LOG_FATAL", StringPiece(...)) 
#endif  // OS_NACL

below instead.

[rkuksin, 2016/10/06 08:50:33]

Done.

+#endif  // !defined(NACL_TC_REV)
+}
+
 // Helper functions to wrap platform differences.
 
 int32_t CurrentProcessId() {
@@ -537,6 +560,10 @@ LogMessage::~LogMessage() {
   stream_ << std::endl;
   std::string str_newline(stream_.str());
 
+  if (severity_ == LOG_FATAL) {
+    SetLogFatalCrashKey(message_start_, str_newline);
+  }
+
   // Give any log message handler first dibs on the message.
   if (log_message_handler &&
       log_message_handler(severity_, file_, line_,