--- a/gfx/layers/apz/src/APZCTreeManager.cpp
+++ b/gfx/layers/apz/src/APZCTreeManager.cpp
@@ -1873,16 +1873,18 @@ APZCTreeManager::ProcessTouchVelocity(ui
   if (mApzcForInputBlock) {
     mApzcForInputBlock->HandleTouchVelocity(aTimestampMs, aSpeedY);
   }
 }
 
 void
 APZCTreeManager::SetKeyboardMap(const KeyboardMap& aKeyboardMap)
 {
+  APZThreadUtils::AssertOnControllerThread();
+
   mKeyboardMap = aKeyboardMap;
 }
 
 void
 APZCTreeManager::ZoomToRect(const ScrollableLayerGuid& aGuid,
                             const CSSRect& aRect,
                             const uint32_t aFlags)
 {

--- a/gfx/layers/apz/src/APZCTreeManager.h
+++ b/gfx/layers/apz/src/APZCTreeManager.h
@@ -694,16 +694,17 @@ private:
    * IMPORTANT: See the note about lock ordering at the top of this file. */
   mutable mozilla::RecursiveMutex mTreeLock;
   RefPtr<HitTestingTreeNode> mRootNode;
   /* Holds the zoom constraints for scrollable layers, as determined by the
    * the main-thread gecko code. */
   std::unordered_map<ScrollableLayerGuid, ZoomConstraints, ScrollableLayerGuidHash> mZoomConstraints;
   /* A list of keyboard shortcuts to use for translating keyboard inputs into
    * keyboard actions. This is gathered on the main thread from XBL bindings.
+   * This must only be accessed on the controller thread.
    */
   KeyboardMap mKeyboardMap;
   /* This tracks the focus targets of chrome and content and whether we have
    * a current focus target or whether we are waiting for a new confirmation.
    */
   FocusState mFocusState;
   /* This tracks the APZC that should receive all inputs for the current input event block.
    * This allows touch points to move outside the thing they started on, but still have the

--- a/gfx/layers/ipc/APZCTreeManagerParent.cpp
+++ b/gfx/layers/ipc/APZCTreeManagerParent.cpp
@@ -161,17 +161,21 @@ APZCTreeManagerParent::RecvReceiveKeyboa
   *aOutEvent = event;
 
   return IPC_OK();
 }
 
 mozilla::ipc::IPCResult
 APZCTreeManagerParent::RecvSetKeyboardMap(const KeyboardMap& aKeyboardMap)
 {
-  mTreeManager->SetKeyboardMap(aKeyboardMap);
+  APZThreadUtils::RunOnControllerThread(NewRunnableMethod<KeyboardMap>(
+    "layers::IAPZCTreeManager::SetKeyboardMap",
+    mTreeManager,
+    &IAPZCTreeManager::SetKeyboardMap,
+    aKeyboardMap));
 
   return IPC_OK();
 }
 
 mozilla::ipc::IPCResult
 APZCTreeManagerParent::RecvZoomToRect(
     const ScrollableLayerGuid& aGuid,
     const CSSRect& aRect,

--- a/widget/nsBaseWidget.cpp
+++ b/widget/nsBaseWidget.cpp
@@ -928,24 +928,31 @@ already_AddRefed<GeckoContentController>
 nsBaseWidget::CreateRootContentController()
 {
   RefPtr<GeckoContentController> controller = new ChromeProcessController(this, mAPZEventState, mAPZC);
   return controller.forget();
 }
 
 void nsBaseWidget::ConfigureAPZCTreeManager()
 {
+  MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(mAPZC);
 
   ConfigureAPZControllerThread();
 
   mAPZC->SetDPI(GetDPI());
 
   if (gfxPrefs::APZKeyboardEnabled()) {
-    mAPZC->SetKeyboardMap(nsXBLWindowKeyHandler::CollectKeyboardShortcuts());
+    KeyboardMap map = nsXBLWindowKeyHandler::CollectKeyboardShortcuts();
+    // On Android the main thread is not the controller thread
+    APZThreadUtils::RunOnControllerThread(NewRunnableMethod<KeyboardMap>(
+        "layers::IAPZCTreeManager::SetKeyboardMap",
+        mAPZC,
+        &IAPZCTreeManager::SetKeyboardMap,
+        map));
   }
 
   RefPtr<IAPZCTreeManager> treeManager = mAPZC;  // for capture by the lambdas
 
   ContentReceivedInputBlockCallback callback(
       [treeManager](const ScrollableLayerGuid& aGuid,
                     uint64_t aInputBlockId,
                     bool aPreventDefault)