Add m-esr52 at 52.6.0

1 files changed, 731 insertions, 0 deletions

diff --git a/gfx/layers/apz/src/InputQueue.cpp b/gfx/layers/apz/src/InputQueue.cpp
new file mode 100644
index 000000000..820526d52
--- /dev/null
+++ b/gfx/layers/apz/src/InputQueue.cpp
@@ -0,0 +1,731 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et tw=80 : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "InputQueue.h"
+
+#include "AsyncPanZoomController.h"
+#include "gfxPrefs.h"
+#include "InputBlockState.h"
+#include "LayersLogging.h"
+#include "mozilla/layers/APZThreadUtils.h"
+#include "OverscrollHandoffState.h"
+#include "QueuedInput.h"
+
+#define INPQ_LOG(...)
+// #define INPQ_LOG(...) printf_stderr("INPQ: " __VA_ARGS__)
+
+namespace mozilla {
+namespace layers {
+
+InputQueue::InputQueue()
+{
+}
+
+InputQueue::~InputQueue() {
+  mQueuedInputs.Clear();
+}
+
+nsEventStatus
+InputQueue::ReceiveInputEvent(const RefPtr<AsyncPanZoomController>& aTarget,
+                              bool aTargetConfirmed,
+                              const InputData& aEvent,
+                              uint64_t* aOutInputBlockId) {
+  APZThreadUtils::AssertOnControllerThread();
+
+  switch (aEvent.mInputType) {
+    case MULTITOUCH_INPUT: {
+      const MultiTouchInput& event = aEvent.AsMultiTouchInput();
+      return ReceiveTouchInput(aTarget, aTargetConfirmed, event, aOutInputBlockId);
+    }
+
+    case SCROLLWHEEL_INPUT: {
+      const ScrollWheelInput& event = aEvent.AsScrollWheelInput();
+      return ReceiveScrollWheelInput(aTarget, aTargetConfirmed, event, aOutInputBlockId);
+    }
+
+    case PANGESTURE_INPUT: {
+      const PanGestureInput& event = aEvent.AsPanGestureInput();
+      return ReceivePanGestureInput(aTarget, aTargetConfirmed, event, aOutInputBlockId);
+    }
+
+    case MOUSE_INPUT: {
+      const MouseInput& event = aEvent.AsMouseInput();
+      return ReceiveMouseInput(aTarget, aTargetConfirmed, event, aOutInputBlockId);
+    }
+
+    default:
+      // The return value for non-touch input is only used by tests, so just pass
+      // through the return value for now. This can be changed later if needed.
+      // TODO (bug 1098430): we will eventually need to have smarter handling for
+      // non-touch events as well.
+      return aTarget->HandleInputEvent(aEvent, aTarget->GetTransformToThis());
+  }
+}
+
+nsEventStatus
+InputQueue::ReceiveTouchInput(const RefPtr<AsyncPanZoomController>& aTarget,
+                              bool aTargetConfirmed,
+                              const MultiTouchInput& aEvent,
+                              uint64_t* aOutInputBlockId) {
+  TouchBlockState* block = nullptr;
+  if (aEvent.mType == MultiTouchInput::MULTITOUCH_START) {
+    nsTArray<TouchBehaviorFlags> currentBehaviors;
+    bool haveBehaviors = false;
+    if (!gfxPrefs::TouchActionEnabled()) {
+      haveBehaviors = true;
+    } else if (mActiveTouchBlock) {
+      haveBehaviors = mActiveTouchBlock->GetAllowedTouchBehaviors(currentBehaviors);
+      // If the behaviours aren't set, but the main-thread response timer on
+      // the block is expired we still treat it as though it has behaviors,
+      // because in that case we still want to interrupt the fast-fling and
+      // use the default behaviours.
+      haveBehaviors |= mActiveTouchBlock->IsContentResponseTimerExpired();
+    }
+
+    block = StartNewTouchBlock(aTarget, aTargetConfirmed, false);
+    INPQ_LOG("started new touch block %p id %" PRIu64 " for target %p\n",
+        block, block->GetBlockId(), aTarget.get());
+
+    // XXX using the chain from |block| here may be wrong in cases where the
+    // target isn't confirmed and the real target turns out to be something
+    // else. For now assume this is rare enough that it's not an issue.
+    if (mQueuedInputs.IsEmpty() &&
+        aEvent.mTouches.Length() == 1 &&
+        block->GetOverscrollHandoffChain()->HasFastFlungApzc() &&
+        haveBehaviors) {
+      // If we're already in a fast fling, and a single finger goes down, then
+      // we want special handling for the touch event, because it shouldn't get
+      // delivered to content. Note that we don't set this flag when going
+      // from a fast fling to a pinch state (i.e. second finger goes down while
+      // the first finger is moving).
+      block->SetDuringFastFling();
+      block->SetConfirmedTargetApzc(aTarget,
+          InputBlockState::TargetConfirmationState::eConfirmed,
+          nullptr /* the block was just created so it has no events */);
+      if (gfxPrefs::TouchActionEnabled()) {
+        block->SetAllowedTouchBehaviors(currentBehaviors);
+      }
+      INPQ_LOG("block %p tagged as fast-motion\n", block);
+    }
+
+    CancelAnimationsForNewBlock(block);
+
+    MaybeRequestContentResponse(aTarget, block);
+  } else {
+    block = mActiveTouchBlock.get();
+    if (!block) {
+      NS_WARNING("Received a non-start touch event while no touch blocks active!");
+      return nsEventStatus_eIgnore;
+    }
+
+    INPQ_LOG("received new event in block %p\n", block);
+  }
+
+  if (aOutInputBlockId) {
+    *aOutInputBlockId = block->GetBlockId();
+  }
+
+  // Note that the |aTarget| the APZCTM sent us may contradict the confirmed
+  // target set on the block. In this case the confirmed target (which may be
+  // null) should take priority. This is equivalent to just always using the
+  // target (confirmed or not) from the block.
+  RefPtr<AsyncPanZoomController> target = block->GetTargetApzc();
+
+  nsEventStatus result = nsEventStatus_eIgnore;
+
+  // XXX calling ArePointerEventsConsumable on |target| may be wrong here if
+  // the target isn't confirmed and the real target turns out to be something
+  // else. For now assume this is rare enough that it's not an issue.
+  if (block->IsDuringFastFling()) {
+    INPQ_LOG("dropping event due to block %p being in fast motion\n", block);
+    result = nsEventStatus_eConsumeNoDefault;
+  } else if (target && target->ArePointerEventsConsumable(block, aEvent.mTouches.Length())) {
+    if (block->UpdateSlopState(aEvent, true)) {
+      INPQ_LOG("dropping event due to block %p being in slop\n", block);
+      result = nsEventStatus_eConsumeNoDefault;
+    } else {
+      result = nsEventStatus_eConsumeDoDefault;
+    }
+  } else if (block->UpdateSlopState(aEvent, false)) {
+    INPQ_LOG("dropping event due to block %p being in mini-slop\n", block);
+    result = nsEventStatus_eConsumeNoDefault;
+  }
+  mQueuedInputs.AppendElement(MakeUnique<QueuedInput>(aEvent, *block));
+  ProcessQueue();
+  return result;
+}
+
+nsEventStatus
+InputQueue::ReceiveMouseInput(const RefPtr<AsyncPanZoomController>& aTarget,
+                              bool aTargetConfirmed,
+                              const MouseInput& aEvent,
+                              uint64_t* aOutInputBlockId) {
+  // On a new mouse down we can have a new target so we must force a new block
+  // with a new target.
+  bool newBlock = DragTracker::StartsDrag(aEvent);
+
+  DragBlockState* block = newBlock ? nullptr : mActiveDragBlock.get();
+  if (block && block->HasReceivedMouseUp()) {
+    block = nullptr;
+  }
+
+  if (!block && mDragTracker.InDrag()) {
+    // If there's no current drag block, but we're getting a move with a button
+    // down, we need to start a new drag block because we're obviously already
+    // in the middle of a drag (it probably got interrupted by something else).
+    INPQ_LOG("got a drag event outside a drag block, need to create a block to hold it\n");
+    newBlock = true;
+  }
+
+  mDragTracker.Update(aEvent);
+
+  if (!newBlock && !block) {
+    // This input event is not in a drag block, so we're not doing anything
+    // with it, return eIgnore.
+    return nsEventStatus_eIgnore;
+  }
+
+  if (!block) {
+    MOZ_ASSERT(newBlock);
+    block = new DragBlockState(aTarget, aTargetConfirmed, aEvent);
+
+    INPQ_LOG("started new drag block %p id %" PRIu64 " for %sconfirmed target %p\n",
+        block, block->GetBlockId(), aTargetConfirmed ? "" : "un", aTarget.get());
+
+    mActiveDragBlock = block;
+
+    CancelAnimationsForNewBlock(block);
+    MaybeRequestContentResponse(aTarget, block);
+  }
+
+  if (aOutInputBlockId) {
+    *aOutInputBlockId = block->GetBlockId();
+  }
+
+  mQueuedInputs.AppendElement(MakeUnique<QueuedInput>(aEvent, *block));
+  ProcessQueue();
+
+  if (DragTracker::EndsDrag(aEvent)) {
+    block->MarkMouseUpReceived();
+  }
+
+  // The event is part of a drag block and could potentially cause
+  // scrolling, so return DoDefault.
+  return nsEventStatus_eConsumeDoDefault;
+}
+
+nsEventStatus
+InputQueue::ReceiveScrollWheelInput(const RefPtr<AsyncPanZoomController>& aTarget,
+                                    bool aTargetConfirmed,
+                                    const ScrollWheelInput& aEvent,
+                                    uint64_t* aOutInputBlockId) {
+  WheelBlockState* block = mActiveWheelBlock.get();
+  // If the block is not accepting new events we'll create a new input block
+  // (and therefore a new wheel transaction).
+  if (block &&
+      (!block->ShouldAcceptNewEvent() ||
+       block->MaybeTimeout(aEvent)))
+  {
+    block = nullptr;
+  }
+
+  MOZ_ASSERT(!block || block->InTransaction());
+
+  if (!block) {
+    block = new WheelBlockState(aTarget, aTargetConfirmed, aEvent);
+    INPQ_LOG("started new scroll wheel block %p id %" PRIu64 " for target %p\n",
+        block, block->GetBlockId(), aTarget.get());
+
+    mActiveWheelBlock = block;
+
+    CancelAnimationsForNewBlock(block);
+    MaybeRequestContentResponse(aTarget, block);
+  } else {
+    INPQ_LOG("received new event in block %p\n", block);
+  }
+
+  if (aOutInputBlockId) {
+    *aOutInputBlockId = block->GetBlockId();
+  }
+
+  // Note that the |aTarget| the APZCTM sent us may contradict the confirmed
+  // target set on the block. In this case the confirmed target (which may be
+  // null) should take priority. This is equivalent to just always using the
+  // target (confirmed or not) from the block, which is what
+  // ProcessQueue() does.
+  mQueuedInputs.AppendElement(MakeUnique<QueuedInput>(aEvent, *block));
+
+  // The WheelBlockState needs to affix a counter to the event before we process
+  // it. Note that the counter is affixed to the copy in the queue rather than
+  // |aEvent|.
+  block->Update(mQueuedInputs.LastElement()->Input()->AsScrollWheelInput());
+
+  ProcessQueue();
+
+  return nsEventStatus_eConsumeDoDefault;
+}
+
+static bool
+CanScrollTargetHorizontally(const PanGestureInput& aInitialEvent,
+                            PanGestureBlockState* aBlock)
+{
+  PanGestureInput horizontalComponent = aInitialEvent;
+  horizontalComponent.mPanDisplacement.y = 0;
+  RefPtr<AsyncPanZoomController> horizontallyScrollableAPZC =
+    aBlock->GetOverscrollHandoffChain()->FindFirstScrollable(horizontalComponent);
+  return horizontallyScrollableAPZC && horizontallyScrollableAPZC == aBlock->GetTargetApzc();
+}
+
+nsEventStatus
+InputQueue::ReceivePanGestureInput(const RefPtr<AsyncPanZoomController>& aTarget,
+                                   bool aTargetConfirmed,
+                                   const PanGestureInput& aEvent,
+                                   uint64_t* aOutInputBlockId) {
+  if (aEvent.mType == PanGestureInput::PANGESTURE_MAYSTART ||
+      aEvent.mType == PanGestureInput::PANGESTURE_CANCELLED) {
+    // Ignore these events for now.
+    return nsEventStatus_eConsumeDoDefault;
+  }
+
+  PanGestureBlockState* block = nullptr;
+  if (aEvent.mType != PanGestureInput::PANGESTURE_START) {
+    block = mActivePanGestureBlock.get();
+  }
+
+  PanGestureInput event = aEvent;
+  nsEventStatus result = nsEventStatus_eConsumeDoDefault;
+
+  if (!block || block->WasInterrupted()) {
+    if (event.mType != PanGestureInput::PANGESTURE_START) {
+      // Only PANGESTURE_START events are allowed to start a new pan gesture
+      // block, but we really want to start a new block here, so we magically
+      // turn this input into a PANGESTURE_START.
+      INPQ_LOG("transmogrifying pan input %d to PANGESTURE_START for new block\n",
+          event.mType);
+      event.mType = PanGestureInput::PANGESTURE_START;
+    }
+    block = new PanGestureBlockState(aTarget, aTargetConfirmed, event);
+    INPQ_LOG("started new pan gesture block %p id %" PRIu64 " for target %p\n",
+        block, block->GetBlockId(), aTarget.get());
+
+    if (aTargetConfirmed &&
+        event.mRequiresContentResponseIfCannotScrollHorizontallyInStartDirection &&
+        !CanScrollTargetHorizontally(event, block)) {
+      // This event may trigger a swipe gesture, depending on what our caller
+      // wants to do it. We need to suspend handling of this block until we get
+      // a content response which will tell us whether to proceed or abort the
+      // block.
+      block->SetNeedsToWaitForContentResponse(true);
+
+      // Inform our caller that we haven't scrolled in response to the event
+      // and that a swipe can be started from this event if desired.
+      result = nsEventStatus_eIgnore;
+    }
+
+    mActivePanGestureBlock = block;
+
+    CancelAnimationsForNewBlock(block);
+    MaybeRequestContentResponse(aTarget, block);
+  } else {
+    INPQ_LOG("received new event in block %p\n", block);
+  }
+
+  if (aOutInputBlockId) {
+    *aOutInputBlockId = block->GetBlockId();
+  }
+
+  // Note that the |aTarget| the APZCTM sent us may contradict the confirmed
+  // target set on the block. In this case the confirmed target (which may be
+  // null) should take priority. This is equivalent to just always using the
+  // target (confirmed or not) from the block, which is what
+  // ProcessQueue() does.
+  mQueuedInputs.AppendElement(MakeUnique<QueuedInput>(event, *block));
+  ProcessQueue();
+
+  return result;
+}
+
+void
+InputQueue::CancelAnimationsForNewBlock(CancelableBlockState* aBlock)
+{
+  // We want to cancel animations here as soon as possible (i.e. without waiting for
+  // content responses) because a finger has gone down and we don't want to keep moving
+  // the content under the finger. However, to prevent "future" touchstart events from
+  // interfering with "past" animations (i.e. from a previous touch block that is still
+  // being processed) we only do this animation-cancellation if there are no older
+  // touch blocks still in the queue.
+  if (mQueuedInputs.IsEmpty()) {
+    aBlock->GetOverscrollHandoffChain()->CancelAnimations(ExcludeOverscroll | ScrollSnap);
+  }
+}
+
+void
+InputQueue::MaybeRequestContentResponse(const RefPtr<AsyncPanZoomController>& aTarget,
+                                        CancelableBlockState* aBlock)
+{
+  bool waitForMainThread = false;
+  if (aBlock->IsTargetConfirmed()) {
+    // Content won't prevent-default this, so we can just set the flag directly.
+    INPQ_LOG("not waiting for content response on block %p\n", aBlock);
+    aBlock->SetContentResponse(false);
+  } else {
+    waitForMainThread = true;
+  }
+  if (aBlock->AsTouchBlock() && gfxPrefs::TouchActionEnabled()) {
+    // waitForMainThread is set to true unconditionally here, but if the APZCTM
+    // has the touch-action behaviours for this block, it will set it
+    // immediately after we unwind out of this ReceiveInputEvent call. So even
+    // though we are scheduling the main-thread timeout, we might end up not
+    // waiting.
+    INPQ_LOG("waiting for main thread touch-action info on block %p\n", aBlock);
+    waitForMainThread = true;
+  }
+  if (waitForMainThread) {
+    // We either don't know for sure if aTarget is the right APZC, or we may
+    // need to wait to give content the opportunity to prevent-default the
+    // touch events. Either way we schedule a timeout so the main thread stuff
+    // can run.
+    ScheduleMainThreadTimeout(aTarget, aBlock);
+  }
+}
+
+uint64_t
+InputQueue::InjectNewTouchBlock(AsyncPanZoomController* aTarget)
+{
+  TouchBlockState* block = StartNewTouchBlock(aTarget,
+    /* aTargetConfirmed = */ true,
+    /* aCopyPropertiesFromCurrent = */ true);
+  INPQ_LOG("injecting new touch block %p with id %" PRIu64 " and target %p\n",
+    block, block->GetBlockId(), aTarget);
+  ScheduleMainThreadTimeout(aTarget, block);
+  return block->GetBlockId();
+}
+
+TouchBlockState*
+InputQueue::StartNewTouchBlock(const RefPtr<AsyncPanZoomController>& aTarget,
+                               bool aTargetConfirmed,
+                               bool aCopyPropertiesFromCurrent)
+{
+  TouchBlockState* newBlock = new TouchBlockState(aTarget, aTargetConfirmed,
+      mTouchCounter);
+  if (aCopyPropertiesFromCurrent) {
+    // We should never enter here without a current touch block, because this
+    // codepath is invoked from the OnLongPress handler in
+    // AsyncPanZoomController, which should bail out if there is no current
+    // touch block.
+    MOZ_ASSERT(GetCurrentTouchBlock());
+    newBlock->CopyPropertiesFrom(*GetCurrentTouchBlock());
+  }
+
+  mActiveTouchBlock = newBlock;
+  return newBlock;
+}
+
+CancelableBlockState*
+InputQueue::GetCurrentBlock() const
+{
+  APZThreadUtils::AssertOnControllerThread();
+  return mQueuedInputs.IsEmpty() ? nullptr : mQueuedInputs[0]->Block();
+}
+
+TouchBlockState*
+InputQueue::GetCurrentTouchBlock() const
+{
+  CancelableBlockState* block = GetCurrentBlock();
+  return block ? block->AsTouchBlock() : mActiveTouchBlock.get();
+}
+
+WheelBlockState*
+InputQueue::GetCurrentWheelBlock() const
+{
+  CancelableBlockState* block = GetCurrentBlock();
+  return block ? block->AsWheelBlock() : mActiveWheelBlock.get();
+}
+
+DragBlockState*
+InputQueue::GetCurrentDragBlock() const
+{
+  CancelableBlockState* block = GetCurrentBlock();
+  return block ? block->AsDragBlock() : mActiveDragBlock.get();
+}
+
+PanGestureBlockState*
+InputQueue::GetCurrentPanGestureBlock() const
+{
+  CancelableBlockState* block = GetCurrentBlock();
+  return block ? block->AsPanGestureBlock() : mActivePanGestureBlock.get();
+}
+
+WheelBlockState*
+InputQueue::GetActiveWheelTransaction() const
+{
+  WheelBlockState* block = mActiveWheelBlock.get();
+  if (!block || !block->InTransaction()) {
+    return nullptr;
+  }
+  return block;
+}
+
+bool
+InputQueue::HasReadyTouchBlock() const
+{
+  return !mQueuedInputs.IsEmpty() &&
+      mQueuedInputs[0]->Block()->AsTouchBlock() &&
+      mQueuedInputs[0]->Block()->IsReadyForHandling();
+}
+
+bool
+InputQueue::AllowScrollHandoff() const
+{
+  if (GetCurrentWheelBlock()) {
+    return GetCurrentWheelBlock()->AllowScrollHandoff();
+  }
+  if (GetCurrentPanGestureBlock()) {
+    return GetCurrentPanGestureBlock()->AllowScrollHandoff();
+  }
+  return true;
+}
+
+bool
+InputQueue::IsDragOnScrollbar(bool aHitScrollbar)
+{
+  if (!mDragTracker.InDrag()) {
+    return false;
+  }
+  // Now that we know we are in a drag, get the info from the drag tracker.
+  // We keep it in the tracker rather than the block because the block can get
+  // interrupted by something else (like a wheel event) and then a new block
+  // will get created without the info we want. The tracker will persist though.
+  return mDragTracker.IsOnScrollbar(aHitScrollbar);
+}
+
+void
+InputQueue::ScheduleMainThreadTimeout(const RefPtr<AsyncPanZoomController>& aTarget,
+                                      CancelableBlockState* aBlock) {
+  INPQ_LOG("scheduling main thread timeout for target %p\n", aTarget.get());
+  aBlock->StartContentResponseTimer();
+  aTarget->PostDelayedTask(NewRunnableMethod<uint64_t>(this,
+                                                       &InputQueue::MainThreadTimeout,
+                                                       aBlock->GetBlockId()),
+                           gfxPrefs::APZContentResponseTimeout());
+}
+
+CancelableBlockState*
+InputQueue::FindBlockForId(uint64_t aInputBlockId,
+                           InputData** aOutFirstInput)
+{
+  for (const auto& queuedInput : mQueuedInputs) {
+    if (queuedInput->Block()->GetBlockId() == aInputBlockId) {
+      if (aOutFirstInput) {
+        *aOutFirstInput = queuedInput->Input();
+      }
+      return queuedInput->Block();
+    }
+  }
+
+  CancelableBlockState* block = nullptr;
+  if (mActiveTouchBlock && mActiveTouchBlock->GetBlockId() == aInputBlockId) {
+    block = mActiveTouchBlock.get();
+  } else if (mActiveWheelBlock && mActiveWheelBlock->GetBlockId() == aInputBlockId) {
+    block = mActiveWheelBlock.get();
+  } else if (mActiveDragBlock && mActiveDragBlock->GetBlockId() == aInputBlockId) {
+    block = mActiveDragBlock.get();
+  } else if (mActivePanGestureBlock && mActivePanGestureBlock->GetBlockId() == aInputBlockId) {
+    block = mActivePanGestureBlock.get();
+  }
+  // Since we didn't encounter this block while iterating through mQueuedInputs,
+  // it must have no events associated with it at the moment.
+  if (aOutFirstInput) {
+    *aOutFirstInput = nullptr;
+  }
+  return block;
+}
+
+void
+InputQueue::MainThreadTimeout(uint64_t aInputBlockId) {
+  APZThreadUtils::AssertOnControllerThread();
+
+  INPQ_LOG("got a main thread timeout; block=%" PRIu64 "\n", aInputBlockId);
+  bool success = false;
+  InputData* firstInput = nullptr;
+  CancelableBlockState* block = FindBlockForId(aInputBlockId, &firstInput);
+  if (block) {
+    // time out the touch-listener response and also confirm the existing
+    // target apzc in the case where the main thread doesn't get back to us
+    // fast enough.
+    success = block->TimeoutContentResponse();
+    success |= block->SetConfirmedTargetApzc(
+        block->GetTargetApzc(),
+        InputBlockState::TargetConfirmationState::eTimedOut,
+        firstInput);
+  }
+  if (success) {
+    ProcessQueue();
+  }
+}
+
+void
+InputQueue::ContentReceivedInputBlock(uint64_t aInputBlockId, bool aPreventDefault) {
+  APZThreadUtils::AssertOnControllerThread();
+
+  INPQ_LOG("got a content response; block=%" PRIu64 "\n", aInputBlockId);
+  bool success = false;
+  CancelableBlockState* block = FindBlockForId(aInputBlockId, nullptr);
+  if (block) {
+    success = block->SetContentResponse(aPreventDefault);
+    block->RecordContentResponseTime();
+  }
+  if (success) {
+    ProcessQueue();
+  }
+}
+
+void
+InputQueue::SetConfirmedTargetApzc(uint64_t aInputBlockId, const RefPtr<AsyncPanZoomController>& aTargetApzc) {
+  APZThreadUtils::AssertOnControllerThread();
+
+  INPQ_LOG("got a target apzc; block=%" PRIu64 " guid=%s\n",
+    aInputBlockId, aTargetApzc ? Stringify(aTargetApzc->GetGuid()).c_str() : "");
+  bool success = false;
+  InputData* firstInput = nullptr;
+  CancelableBlockState* block = FindBlockForId(aInputBlockId, &firstInput);
+  if (block) {
+    success = block->SetConfirmedTargetApzc(aTargetApzc,
+        InputBlockState::TargetConfirmationState::eConfirmed,
+        firstInput);
+    block->RecordContentResponseTime();
+  }
+  if (success) {
+    ProcessQueue();
+  }
+}
+
+void
+InputQueue::ConfirmDragBlock(uint64_t aInputBlockId, const RefPtr<AsyncPanZoomController>& aTargetApzc,
+                                   const AsyncDragMetrics& aDragMetrics)
+{
+  APZThreadUtils::AssertOnControllerThread();
+
+  INPQ_LOG("got a target apzc; block=%" PRIu64 " guid=%s\n",
+    aInputBlockId, aTargetApzc ? Stringify(aTargetApzc->GetGuid()).c_str() : "");
+  bool success = false;
+  InputData* firstInput = nullptr;
+  CancelableBlockState* block = FindBlockForId(aInputBlockId, &firstInput);
+  if (block && block->AsDragBlock()) {
+    block->AsDragBlock()->SetDragMetrics(aDragMetrics);
+    success = block->SetConfirmedTargetApzc(aTargetApzc,
+        InputBlockState::TargetConfirmationState::eConfirmed,
+        firstInput);
+    block->RecordContentResponseTime();
+  }
+  if (success) {
+    ProcessQueue();
+  }
+}
+
+void
+InputQueue::SetAllowedTouchBehavior(uint64_t aInputBlockId, const nsTArray<TouchBehaviorFlags>& aBehaviors) {
+  APZThreadUtils::AssertOnControllerThread();
+
+  INPQ_LOG("got allowed touch behaviours; block=%" PRIu64 "\n", aInputBlockId);
+  bool success = false;
+  CancelableBlockState* block = FindBlockForId(aInputBlockId, nullptr);
+  if (block && block->AsTouchBlock()) {
+    success = block->AsTouchBlock()->SetAllowedTouchBehaviors(aBehaviors);
+    block->RecordContentResponseTime();
+  } else if (block) {
+    NS_WARNING("input block is not a touch block");
+  }
+  if (success) {
+    ProcessQueue();
+  }
+}
+
+void
+InputQueue::ProcessQueue() {
+  APZThreadUtils::AssertOnControllerThread();
+
+  while (!mQueuedInputs.IsEmpty()) {
+    CancelableBlockState* curBlock = mQueuedInputs[0]->Block();
+    if (!curBlock->IsReadyForHandling()) {
+      break;
+    }
+
+    INPQ_LOG("processing input from block %p; preventDefault %d target %p\n",
+        curBlock, curBlock->IsDefaultPrevented(),
+        curBlock->GetTargetApzc().get());
+    RefPtr<AsyncPanZoomController> target = curBlock->GetTargetApzc();
+    // target may be null here if the initial target was unconfirmed and then
+    // we later got a confirmed null target. in that case drop the events.
+    if (target) {
+      if (curBlock->IsDefaultPrevented()) {
+        if (curBlock->AsTouchBlock()) {
+          target->ResetTouchInputState();
+        }
+      } else {
+        UpdateActiveApzc(target);
+        curBlock->DispatchEvent(*(mQueuedInputs[0]->Input()));
+      }
+    }
+    mQueuedInputs.RemoveElementAt(0);
+  }
+
+  if (CanDiscardBlock(mActiveTouchBlock)) {
+    mActiveTouchBlock = nullptr;
+  }
+  if (CanDiscardBlock(mActiveWheelBlock)) {
+    mActiveWheelBlock = nullptr;
+  }
+  if (CanDiscardBlock(mActiveDragBlock)) {
+    mActiveDragBlock = nullptr;
+  }
+  if (CanDiscardBlock(mActivePanGestureBlock)) {
+    mActivePanGestureBlock = nullptr;
+  }
+}
+
+bool
+InputQueue::CanDiscardBlock(CancelableBlockState* aBlock)
+{
+  if (!aBlock ||
+      !aBlock->IsReadyForHandling() ||
+      aBlock->MustStayActive()) {
+    return false;
+  }
+  InputData* firstInput = nullptr;
+  FindBlockForId(aBlock->GetBlockId(), &firstInput);
+  if (firstInput) {
+    // The block has at least one input event still in the queue, so it's
+    // not depleted
+    return false;
+  }
+  return true;
+}
+
+void
+InputQueue::UpdateActiveApzc(const RefPtr<AsyncPanZoomController>& aNewActive) {
+  if (mLastActiveApzc && mLastActiveApzc != aNewActive
+      && mTouchCounter.GetActiveTouchCount() > 0) {
+    mLastActiveApzc->ResetTouchInputState();
+  }
+  mLastActiveApzc = aNewActive;
+}
+
+void
+InputQueue::Clear()
+{
+  APZThreadUtils::AssertOnControllerThread();
+
+  mQueuedInputs.Clear();
+  mActiveTouchBlock = nullptr;
+  mActiveWheelBlock = nullptr;
+  mActiveDragBlock = nullptr;
+  mActivePanGestureBlock = nullptr;
+  mLastActiveApzc = nullptr;
+}
+
+} // namespace layers
+} // namespace mozilla