diff --git a/js/src/builtin/TestingFunctions.cpp b/js/src/builtin/TestingFunctions.cpp
index 1cd1f5a79dcf..dc1757251019 100644
--- a/js/src/builtin/TestingFunctions.cpp
+++ b/js/src/builtin/TestingFunctions.cpp
@@ -2527,7 +2527,7 @@ testingFunc_inIon(JSContext* cx, unsigned argc, Value* vp)
     ScriptFrameIter iter(cx);
     if (!iter.done() && iter.isIon()) {
         // Reset the counter of the IonScript's script.
-        jit::JSJitFrameIter jitIter(cx);
+        jit::JSJitFrameIter jitIter(cx->activation()->asJit());
         ++jitIter;
         jitIter.script()->resetWarmUpResetCounter();
     } else {
diff --git a/js/src/jit/BaselineBailouts.cpp b/js/src/jit/BaselineBailouts.cpp
index c7536cb993b4..3a91cf020e3e 100644
--- a/js/src/jit/BaselineBailouts.cpp
+++ b/js/src/jit/BaselineBailouts.cpp
@@ -1900,7 +1900,7 @@ jit::FinishBailoutToBaseline(BaselineBailoutInfo* bailoutInfo)
     RootedScript outerScript(cx, nullptr);
 
     MOZ_ASSERT(cx->currentlyRunningInJit());
-    JSJitFrameIter iter(cx);
+    JSJitFrameIter iter(cx->activation()->asJit());
     uint8_t* outerFp = nullptr;
 
     // Iter currently points at the exit frame.  Get the previous frame
@@ -1962,7 +1962,7 @@ jit::FinishBailoutToBaseline(BaselineBailoutInfo* bailoutInfo)
     // on.
     JitActivation* act = cx->activation()->asJit();
     if (act->hasRematerializedFrame(outerFp)) {
-        JSJitFrameIter iter(cx);
+        JSJitFrameIter iter(cx->activation()->asJit());
         size_t inlineDepth = numFrames;
         bool ok = true;
         while (inlineDepth > 0) {
diff --git a/js/src/jit/BaselineDebugModeOSR.cpp b/js/src/jit/BaselineDebugModeOSR.cpp
index f8ff5f237fd0..5a6d2d4b9a11 100644
--- a/js/src/jit/BaselineDebugModeOSR.cpp
+++ b/js/src/jit/BaselineDebugModeOSR.cpp
@@ -1186,7 +1186,7 @@ JitRuntime::generateBaselineDebugModeOSRHandler(JSContext* cx, uint32_t* noFrame
 
 /* static */ void
 DebugModeOSRVolatileJitFrameIter::forwardLiveIterators(const CooperatingContext& cx,
-                                                         uint8_t* oldAddr, uint8_t* newAddr)
+                                                       uint8_t* oldAddr, uint8_t* newAddr)
 {
     DebugModeOSRVolatileJitFrameIter* iter;
     for (iter = cx.context()->liveVolatileJitFrameIter_; iter; iter = iter->prev)
diff --git a/js/src/jit/BaselineFrame.cpp b/js/src/jit/BaselineFrame.cpp
index 4b31580815ff..7f8c619ebd42 100644
--- a/js/src/jit/BaselineFrame.cpp
+++ b/js/src/jit/BaselineFrame.cpp
@@ -142,7 +142,7 @@ BaselineFrame::initForOsr(InterpreterFrame* fp, uint32_t numStackValues)
         // debugger, wants a valid return address, but it's okay to just pick one.
         // In debug mode there's always at least 1 ICEntry (since there are always
         // debug prologue/epilogue calls).
-        JSJitFrameIter frame(cx);
+        JSJitFrameIter frame(cx->activation()->asJit());
         MOZ_ASSERT(frame.returnAddress() == nullptr);
         BaselineScript* baseline = fp->script()->baselineScript();
         frame.current()->setReturnAddress(baseline->returnAddressForIC(baseline->icEntry(0)));
diff --git a/js/src/jit/IonCacheIRCompiler.cpp b/js/src/jit/IonCacheIRCompiler.cpp
index b8a53f776083..83c5a9274fc3 100644
--- a/js/src/jit/IonCacheIRCompiler.cpp
+++ b/js/src/jit/IonCacheIRCompiler.cpp
@@ -327,7 +327,7 @@ CacheRegisterAllocator::restoreIonLiveRegisters(MacroAssembler& masm, LiveRegist
 static void*
 GetReturnAddressToIonCode(JSContext* cx)
 {
-    JSJitFrameIter frame(cx);
+    JSJitFrameIter frame(cx->activation()->asJit());
     MOZ_ASSERT(frame.type() == JitFrame_Exit,
                "An exit frame is expected as update functions are called with a VMFunction.");
 
diff --git a/js/src/jit/JSJitFrameIter.cpp b/js/src/jit/JSJitFrameIter.cpp
index f1406a867ff1..88c57f15c029 100644
--- a/js/src/jit/JSJitFrameIter.cpp
+++ b/js/src/jit/JSJitFrameIter.cpp
@@ -31,11 +31,6 @@ JSJitFrameIter::JSJitFrameIter(const JitActivation* activation)
     }
 }
 
-JSJitFrameIter::JSJitFrameIter(JSContext* cx)
-  : JSJitFrameIter(cx->activation()->asJit())
-{
-}
-
 bool
 JSJitFrameIter::checkInvalidation() const
 {
diff --git a/js/src/jit/JSJitFrameIter.h b/js/src/jit/JSJitFrameIter.h
index fe55e99e833b..1ac3d99a0268 100644
--- a/js/src/jit/JSJitFrameIter.h
+++ b/js/src/jit/JSJitFrameIter.h
@@ -112,7 +112,6 @@ class JSJitFrameIter
   public:
     // See comment above the class.
     explicit JSJitFrameIter(const JitActivation* activation);
-    explicit JSJitFrameIter(JSContext* cx);
 
     // Used only by DebugModeOSRVolatileJitFrameIter.
     void exchangeReturnAddressIfMatch(uint8_t* oldAddr, uint8_t* newAddr) {
diff --git a/js/src/jit/JitFrames-inl.h b/js/src/jit/JitFrames-inl.h
index 251714e62f8c..7f1efbae77c4 100644
--- a/js/src/jit/JitFrames-inl.h
+++ b/js/src/jit/JitFrames-inl.h
@@ -29,7 +29,7 @@ SafepointIndex::resolve()
 inline BaselineFrame*
 GetTopBaselineFrame(JSContext* cx)
 {
-    JSJitFrameIter frame(cx);
+    JSJitFrameIter frame(cx->activation()->asJit());
     MOZ_ASSERT(frame.type() == JitFrame_Exit);
     ++frame;
     if (frame.isBaselineStub())
diff --git a/js/src/jit/JitFrames.cpp b/js/src/jit/JitFrames.cpp
index 7011ad84dfc8..01e685b9e5b3 100644
--- a/js/src/jit/JitFrames.cpp
+++ b/js/src/jit/JitFrames.cpp
@@ -746,7 +746,7 @@ HandleException(ResumeFromException* rfe)
             // see this frame when they use ScriptFrameIter, and (2)
             // ScriptFrameIter does not crash when accessing an IonScript
             // that's destroyed by the ionScript->decref call.
-            EnsureBareExitFrame(cx, current);
+            EnsureBareExitFrame(cx->activation()->asJit(), current);
         }
 
         if (overrecursed) {
@@ -763,11 +763,11 @@ HandleException(ResumeFromException* rfe)
 // Turns a JitFrameLayout into an ExitFrameLayout. Note that it has to be a
 // bare exit frame so it's ignored by TraceJitExitFrame.
 void
-EnsureBareExitFrame(JSContext* cx, JitFrameLayout* frame)
+EnsureBareExitFrame(JitActivation* act, JitFrameLayout* frame)
 {
     ExitFrameLayout* exitFrame = reinterpret_cast<ExitFrameLayout*>(frame);
 
-    if (cx->activation()->asJit()->jsExitFP() == (uint8_t*)frame) {
+    if (act->jsExitFP() == (uint8_t*)frame) {
         // If we already called this function for the current frame, do
         // nothing.
         MOZ_ASSERT(exitFrame->isBareExit());
@@ -775,17 +775,17 @@ EnsureBareExitFrame(JSContext* cx, JitFrameLayout* frame)
     }
 
 #ifdef DEBUG
-    JSJitFrameIter iter(cx);
+    JSJitFrameIter iter(act);
     while (!iter.isScripted())
         ++iter;
     MOZ_ASSERT(iter.current() == frame, "|frame| must be the top JS frame");
 
-    MOZ_ASSERT(!!cx->activation()->asJit()->jsExitFP());
-    MOZ_ASSERT((uint8_t*)exitFrame->footer() >= cx->activation()->asJit()->jsExitFP(),
+    MOZ_ASSERT(!!act->jsExitFP());
+    MOZ_ASSERT((uint8_t*)exitFrame->footer() >= act->jsExitFP(),
                "Must have space for ExitFooterFrame before jsExitFP");
 #endif
 
-    cx->activation()->asJit()->setJSExitFP((uint8_t*)frame);
+    act->setJSExitFP((uint8_t*)frame);
     exitFrame->footer()->setBareExitFrame();
     MOZ_ASSERT(exitFrame->isBareExit());
 }
diff --git a/js/src/jit/JitFrames.h b/js/src/jit/JitFrames.h
index 1b616645dbee..ff313d503ca3 100644
--- a/js/src/jit/JitFrames.h
+++ b/js/src/jit/JitFrames.h
@@ -284,7 +284,7 @@ struct ResumeFromException
 
 void HandleException(ResumeFromException* rfe);
 
-void EnsureBareExitFrame(JSContext* cx, JitFrameLayout* frame);
+void EnsureBareExitFrame(JitActivation* act, JitFrameLayout* frame);
 
 void TraceJitActivations(JSContext* cx, const CooperatingContext& target, JSTracer* trc);
 
@@ -312,7 +312,7 @@ MakeFrameDescriptor(uint32_t frameSize, FrameType type, uint32_t headerSize)
 inline JSScript*
 GetTopJitJSScript(JSContext* cx)
 {
-    JSJitFrameIter frame(cx);
+    JSJitFrameIter frame(cx->activation()->asJit());
     MOZ_ASSERT(frame.type() == JitFrame_Exit);
     ++frame;
 
diff --git a/js/src/jit/VMFunctions.cpp b/js/src/jit/VMFunctions.cpp
index 28d37b990d47..b0a9755a5bd8 100644
--- a/js/src/jit/VMFunctions.cpp
+++ b/js/src/jit/VMFunctions.cpp
@@ -391,7 +391,7 @@ ArrayPushDense(JSContext* cx, HandleArrayObject arr, HandleValue v, uint32_t* le
     // possible the setOrExtendDenseElements call already invalidated the
     // IonScript. JSJitFrameIter::ionScript works when the script is invalidated
     // so we use that instead.
-    JSJitFrameIter frame(cx);
+    JSJitFrameIter frame(cx->activation()->asJit());
     MOZ_ASSERT(frame.type() == JitFrame_Exit);
     ++frame;
     IonScript* ionScript = frame.ionScript();
@@ -872,7 +872,7 @@ DebugEpilogue(JSContext* cx, BaselineFrame* frame, jsbytecode* pc, bool ok)
         // Pop this frame by updating packedExitFP, so that the exception
         // handling code will start at the previous frame.
         JitFrameLayout* prefix = frame->framePrefix();
-        EnsureBareExitFrame(cx, prefix);
+        EnsureBareExitFrame(cx->activation()->asJit(), prefix);
         return false;
     }