Expose the GC under a name that is less collision prone than window.gc.

src/extensions/gc-extension.cc

Index: src/extensions/gc-extension.cc
diff --git a/src/extensions/gc-extension.cc b/src/extensions/gc-extension.cc
index 813b9219bfec7eacd0638cf002c8abb368bba3d2..c42413be7fadd5580d2eed8c4c3616688944212e 100644
--- a/src/extensions/gc-extension.cc
+++ b/src/extensions/gc-extension.cc
@@ -50,7 +50,15 @@ v8::Handle<v8::Value> GCExtension::GC(const v8::Arguments& args) {
 
 
 void GCExtension::Register() {
-  static GCExtension gc_extension;
+  static char buffer[50];
+  if (FLAG_expose_gc_as != NULL && strlen(FLAG_expose_gc_as) != 0) {
+    snprintf(
+        buffer, sizeof(buffer), "native function %s();", FLAG_expose_gc_as);
+  } else {
+    snprintf(buffer, sizeof(buffer), "native function gc();");
+  }
+
+  static GCExtension gc_extension(buffer);
   static v8::DeclareExtension declaration(&gc_extension);
 }