Misc debugger enhancements and bug fixes....

src/runtime.cc

Index: src/runtime.cc
===================================================================
--- src/runtime.cc	(revision 6165)
+++ src/runtime.cc	(working copy)
@@ -10406,10 +10406,36 @@
 }
 
 
+// Sets a v8 flag.
+static MaybeObject* Runtime_SetFlags(Arguments args) {
+  CONVERT_CHECKED(String, arg, args[0]);
+  SmartPointer<char> flags =
+      arg->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);
+  FlagList::SetFlagsFromString(*flags, strlen(*flags));
+  return Heap::undefined_value();
+}
+
+
+// Performs a GC.
+// Presently, it only does a full GC.
+static MaybeObject* Runtime_CollectGarbage(Arguments args) {
+  Heap::CollectAllGarbage(true);
+  return Heap::undefined_value();
+}
+
+
+// Gets the current heap usage.
+static MaybeObject* Runtime_GetHeapUsage(Arguments args) {
+  int usage = Heap::SizeOfObjects();
+  if (!Smi::IsValid(usage)) {
+    return *Factory::NewNumberFromInt(usage);
+  }
+  return Smi::FromInt(usage);
+}
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
+
 #ifdef ENABLE_LOGGING_AND_PROFILING
-
 static MaybeObject* Runtime_ProfilerResume(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);