Bug 716014, use compartment gc more often, JS API part, r=terrence

--HG--
extra : rebase_source : c61a7552611cfbb0ce39bfee7787da57bec5a637

js/src/jsfriendapi.cpp

@@ -144,6 +144,17 @@ js::PrepareForFullGC(JSRuntime *rt)
         c->scheduleGC();
 }
 
+JS_FRIEND_API(bool)
+js::IsGCScheduled(JSRuntime *rt)
+{
+    for (CompartmentsIter c(rt); !c.done(); c.next()) {
+        if (c->isGCScheduled())
+            return true;
+    }
+
+    return false;
+}
+
 JS_FRIEND_API(void)
 js::GCForReason(JSRuntime *rt, gcreason::Reason reason)
 {

js/src/jsfriendapi.h

@@ -651,6 +651,9 @@ PrepareCompartmentForGC(JSCompartment *comp);
 extern JS_FRIEND_API(void)
 PrepareForFullGC(JSRuntime *rt);
 
+extern JS_FRIEND_API(bool)
+IsGCScheduled(JSRuntime *rt);
+
 /*
  * When triggering a GC using one of the functions below, it is first necessary
  * to select the compartments to be collected. To do this, you can call