Reland "Removed default Isolate."

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 88dae56b7b518d391b0e9dc54d4031b678dd002a..623e08d8fae6b776c0c8dad24d294f6b18132f1f 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -1936,58 +1936,48 @@ void Logger::LogAccessorCallbacks() {
 
 
 static void AddIsolateIdIfNeeded(Isolate* isolate, StringStream* stream) {
-  if (isolate->IsDefaultIsolate() || !FLAG_logfile_per_isolate) return;
-  stream->Add("isolate-%p-", isolate);
+  if (FLAG_logfile_per_isolate) stream->Add("isolate-%p-", isolate);
 }
 
 
 static SmartArrayPointer<const char> PrepareLogFileName(
     Isolate* isolate, const char* file_name) {
-  if (strchr(file_name, '%') != NULL || !isolate->IsDefaultIsolate()) {
-    // If there's a '%' in the log file name we have to expand
-    // placeholders.
-    HeapStringAllocator allocator;
-    StringStream stream(&allocator);
-    AddIsolateIdIfNeeded(isolate, &stream);
-    for (const char* p = file_name; *p; p++) {
-      if (*p == '%') {
-        p++;
-        switch (*p) {
-          case '\0':
-            // If there's a % at the end of the string we back up
-            // one character so we can escape the loop properly.
-            p--;
-            break;
-          case 'p':
-            stream.Add("%d", OS::GetCurrentProcessId());
-            break;
-          case 't': {
-            // %t expands to the current time in milliseconds.
-            double time = OS::TimeCurrentMillis();
-            stream.Add("%.0f", FmtElm(time));
-            break;
-          }
-          case '%':
-            // %% expands (contracts really) to %.
-            stream.Put('%');
-            break;
-          default:
-            // All other %'s expand to themselves.
-            stream.Put('%');
-            stream.Put(*p);
-            break;
+  HeapStringAllocator allocator;
+  StringStream stream(&allocator);
+  AddIsolateIdIfNeeded(isolate, &stream);
+  for (const char* p = file_name; *p; p++) {
+    if (*p == '%') {
+      p++;
+      switch (*p) {
+        case '\0':
+          // If there's a % at the end of the string we back up
+          // one character so we can escape the loop properly.
+          p--;
+          break;
+        case 'p':
+          stream.Add("%d", OS::GetCurrentProcessId());
+          break;
+        case 't': {
+          // %t expands to the current time in milliseconds.
+          double time = OS::TimeCurrentMillis();
+          stream.Add("%.0f", FmtElm(time));
+          break;
         }
-      } else {
-        stream.Put(*p);
+        case '%':
+          // %% expands (contracts really) to %.
+          stream.Put('%');
+          break;
+        default:
+          // All other %'s expand to themselves.
+          stream.Put('%');
+          stream.Put(*p);
+          break;
       }
+    } else {
+      stream.Put(*p);
     }
-    return SmartArrayPointer<const char>(stream.ToCString());
   }
-  int length = StrLength(file_name);
-  char* str = NewArray<char>(length + 1);
-  OS::MemCopy(str, file_name, length);
-  str[length] = '\0';
-  return SmartArrayPointer<const char>(str);
+  return SmartArrayPointer<const char>(stream.ToCString());
 }