Bug 538440 - We never jit DOM workers. r=mrbkap.

dom/src/threads/nsDOMThreadService.cpp

@@ -997,8 +997,7 @@ nsDOMThreadService::CreateJSContext()
   };
   JS_SetContextSecurityCallbacks(cx, &securityCallbacks);
 
-  static JSDebugHooks debugHooks;
-  JS_SetContextDebugHooks(cx, &debugHooks);
+  JS_ClearContextDebugHooks(cx);
 
   nsresult rv = nsContentUtils::XPConnect()->
     SetSecurityManagerForJSContext(cx, gWorkerSecurityManager, 0);

js/src/jscntxt.h

@@ -1072,6 +1072,8 @@ typedef struct JSResolvingEntry {
 
 #define JSRESOLVE_INFER         0xffff  /* infer bits from current bytecode */
 
+extern const JSDebugHooks js_NullDebugHooks;  /* defined in jsdbgapi.cpp */
+
 struct JSContext {
     /*
      * If this flag is set, we were asked to call back the operation callback
@@ -1248,8 +1250,9 @@ struct JSContext {
     void updateJITEnabled() {
 #ifdef JS_TRACER
         jitEnabled = ((options & JSOPTION_JIT) &&
-                      !runtime->debuggerInhibitsJIT() &&
-                      debugHooks == &runtime->globalDebugHooks);
+                      (debugHooks == &js_NullDebugHooks ||
+                       (debugHooks == &runtime->globalDebugHooks &&
+                        !runtime->debuggerInhibitsJIT())));
 #endif
     }
 

js/src/jsdbgapi.cpp

@@ -1828,11 +1828,13 @@ JS_GetGlobalDebugHooks(JSRuntime *rt)
     return &rt->globalDebugHooks;
 }
 
+const JSDebugHooks js_NullDebugHooks = {};
+
 JS_PUBLIC_API(JSDebugHooks *)
 JS_SetContextDebugHooks(JSContext *cx, const JSDebugHooks *hooks)
 {
     JS_ASSERT(hooks);
-    if (hooks != &cx->runtime->globalDebugHooks)
+    if (hooks != &cx->runtime->globalDebugHooks && hooks != &js_NullDebugHooks)
         js_LeaveTrace(cx);
 
 #ifdef JS_TRACER
@@ -1847,6 +1849,12 @@ JS_SetContextDebugHooks(JSContext *cx, const JSDebugHooks *hooks)
     return old;
 }
 
+JS_PUBLIC_API(JSDebugHooks *)
+JS_ClearContextDebugHooks(JSContext *cx)
+{
+    return JS_SetContextDebugHooks(cx, &js_NullDebugHooks);
+}
+
 #ifdef MOZ_SHARK
 
 #include <CHUD/CHUD.h>

js/src/jsdbgapi.h

@@ -427,6 +427,10 @@ JS_GetGlobalDebugHooks(JSRuntime *rt);
 extern JS_PUBLIC_API(JSDebugHooks *)
 JS_SetContextDebugHooks(JSContext *cx, const JSDebugHooks *hooks);
 
+/* Disable debug hooks for this context. */
+extern JS_PUBLIC_API(JSDebugHooks *)
+JS_ClearContextDebugHooks(JSContext *cx);
+
 #ifdef MOZ_SHARK
 
 extern JS_PUBLIC_API(JSBool)