Fix preparing log file name.

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 9861b1b5a68b75961c78a2cebfcd5f655d46220a..458a996fb83d65c30d2dfaecf32c0cdebbb04b05 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -1767,9 +1767,22 @@ static void AddIsolateIdIfNeeded(std::ostream& os,  // NOLINT
 
 static void PrepareLogFileName(std::ostream& os,  // NOLINT
                                Isolate* isolate, const char* file_name) {
-  AddIsolateIdIfNeeded(os, isolate);
+  int slash_count = 0;
   for (const char* p = file_name; *p; p++) {
-    if (*p == '%') {
+    if (base::OS::isDirectorySeparator(*p))
+      slash_count++;

[Yang, 2015/03/03 08:36:57]

no line break after if.

[sejunho, 2015/03/03 10:14:50]

Done.

+  }
+
+  for (const char* p = file_name; *p; p++) {
+    if (slash_count == 0) {
+      AddIsolateIdIfNeeded(os, isolate);
+      slash_count--;
+    }
+
+    if (base::OS::isDirectorySeparator(*p)) {
+      slash_count--;
+      os << *p;
+    } else if (*p == '%') {

[Yang, 2015/03/03 08:36:57]

How about

if (*p == '%') {
  ... 
} else {
  if (base::OS::isDirectorySeparator(*p)) slash_count--;
  os << *p;
}

[sejunho, 2015/03/03 10:14:50]

OK.

       p++;
       switch (*p) {
         case '\0':