Log V8 version in profiler log file.

src/log-utils.cc

Index: src/log-utils.cc
diff --git a/src/log-utils.cc b/src/log-utils.cc
index c94d07a9f29220fab5caeb252381c35821f6970c..caada8bd2f2ee318618b2eea2660c4a15ae653a3 100644
--- a/src/log-utils.cc
+++ b/src/log-utils.cc
@@ -6,6 +6,7 @@
 
 #include "src/log-utils.h"
 #include "src/string-stream.h"
+#include "src/version.h"
 
 namespace v8 {
 namespace internal {
@@ -49,6 +50,17 @@ void Log::Initialize(const char* log_file_name) {
     } else {
       OpenFile(log_file_name);
     }
+
+    if (output_handle_ != nullptr) {
+      Log::MessageBuilder msg(this);
+      msg.Append("v8-version,%d,%d,%d,%d,%d",
+                 Version::GetMajor(),
+                 Version::GetMinor(),
+                 Version::GetBuild(),
+                 Version::GetPatch(),
+                 Version::IsCandidate());
+      msg.WriteToLogFile();
+    }
   }
 }