Bug 854421 - Part 8: Try find a 'root' refresh driver to see if it's blocked. r=vlad

gfx/layers/ipc/PLayerTransaction.ipdl

@@ -58,7 +58,7 @@ parent:
   
   // We don't need to send a sync transaction if
   // no transaction operate require a swap.
-  async UpdateNoSwap(Edit[] cset, uin64_t id, TargetConfig targetConfig, bool isFirstPaint,
+  async UpdateNoSwap(Edit[] cset, uint64_t id, TargetConfig targetConfig, bool isFirstPaint,
                      bool scheduleComposite, uint32_t paintSequenceNumber);
 
   // Testing APIs

layout/base/nsPresShell.cpp

@@ -4039,10 +4039,14 @@ PresShell::FlushPendingNotifications(mozilla::ChangesToFlush aFlush)
 
       if (aFlush.mFlushAnimations &&
           !mPresContext->StyleUpdateForAllAnimationsIsUpToDate()) {
-        mPresContext->AnimationManager()->
-          FlushAnimations(CommonAnimationManager::Cannot_Throttle);
-        mPresContext->TransitionManager()->
-          FlushTransitions(CommonAnimationManager::Cannot_Throttle);
+        if (mPresContext->AnimationManager()) {
+          mPresContext->AnimationManager()->
+            FlushAnimations(CommonAnimationManager::Cannot_Throttle);
+        }
+        if (mPresContext->TransitionManager()) {
+          mPresContext->TransitionManager()->
+            FlushTransitions(CommonAnimationManager::Cannot_Throttle);
+        }
         mPresContext->TickLastStyleUpdateForAllAnimations();
       }
 

layout/base/nsRefreshDriver.cpp

@@ -686,6 +686,7 @@ nsRefreshDriver::nsRefreshDriver(nsPresContext* aPresContext)
     mReflowCause(nullptr),
     mStyleCause(nullptr),
     mPresContext(aPresContext),
+    mRootRefresh(nullptr),
     mPendingTransaction(0),
     mCompletedTransaction(0),
     mFreezeCount(0),
@@ -707,6 +708,10 @@ nsRefreshDriver::~nsRefreshDriver()
                     "observers should have unregistered");
   NS_ABORT_IF_FALSE(!mActiveTimer, "timer should be gone");
   
+  if (mRootRefresh) {
+    mRootRefresh->RemoveRefreshObserver(this, Flush_Style);
+    mRootRefresh = nullptr;
+  }
   for (uint32_t i = 0; i < mPresShellsToInvalidateIfHidden.Length(); i++) {
     mPresShellsToInvalidateIfHidden[i]->InvalidatePresShellIfHidden();
   }
@@ -1065,13 +1070,17 @@ nsRefreshDriver::Tick(int64_t aNowEpoch, TimeStamp aNowTime)
   mMostRecentRefresh = aNowTime;
   mMostRecentRefreshEpochTime = aNowEpoch;
 
-  if (mWaitingForTransaction) {
+  if (IsWaitingForPaint()) {
     // We're currently suspended waiting for earlier Tick's to
     // be completed (on the Compositor). Mark that we missed the paint
     // and keep waiting.
-    mSkippedPaint = true;
     return;
   }
+  if (mRootRefresh) {
+    mRootRefresh->RemoveRefreshObserver(this, Flush_Style);
+    mRootRefresh = nullptr;
+  }
+  mSkippedPaint = false;
 
   nsCOMPtr<nsIPresShell> presShell = mPresContext->GetPresShell();
   if (!presShell || (ObserverCount() == 0 && ImageRequestCount() == 0)) {
@@ -1424,6 +1433,49 @@ nsRefreshDriver::NotifyTransactionCompleted(uint64_t aTransactionId)
   }
 }
 
+void
+nsRefreshDriver::WillRefresh(mozilla::TimeStamp aTime)
+{
+  mRootRefresh->RemoveRefreshObserver(this, Flush_Style);
+  mRootRefresh = nullptr;
+  if (mSkippedPaint) {
+    DoRefresh();
+  }
+}
+
+bool
+nsRefreshDriver::IsWaitingForPaint()
+{
+  if (mTestControllingRefreshes) {
+    return false;
+  }
+  if (mWaitingForTransaction) {
+    mSkippedPaint = true;
+    return true;
+  }
+
+  // Try find the 'root' refresh driver for the current window and check
+  // if that is waiting for a paint.
+  nsPresContext *displayRoot = PresContext()->GetDisplayRootPresContext();
+  if (displayRoot) {
+    nsRefreshDriver *rootRefresh = displayRoot->GetRootPresContext()->RefreshDriver();
+    if (rootRefresh && rootRefresh != this) {
+      if (rootRefresh->IsWaitingForPaint()) {
+        if (mRootRefresh != rootRefresh) {
+          if (mRootRefresh) {
+            mRootRefresh->RemoveRefreshObserver(this, Flush_Style);
+          }
+          rootRefresh->AddRefreshObserver(this, Flush_Style);
+          mRootRefresh = rootRefresh;
+        }
+        mSkippedPaint = true;
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 void
 nsRefreshDriver::SetThrottled(bool aThrottled)
 {

layout/base/nsRefreshDriver.h

@@ -63,7 +63,8 @@ public:
   virtual void DidRefresh() = 0;
 };
 
-class nsRefreshDriver MOZ_FINAL : public mozilla::layers::TransactionIdAllocator {
+class nsRefreshDriver MOZ_FINAL : public mozilla::layers::TransactionIdAllocator,
+                                  public nsARefreshObserver {
 public:
   nsRefreshDriver(nsPresContext *aPresContext);
   ~nsRefreshDriver();
@@ -275,6 +276,12 @@ public:
   void NotifyTransactionCompleted(uint64_t aTransactionId) MOZ_OVERRIDE;
   void RevokeTransactionId(uint64_t aTransactionId) MOZ_OVERRIDE;
 
+  bool IsWaitingForPaint();
+
+  // nsARefreshObserver
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) { return TransactionIdAllocator::AddRef(); }
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) { return TransactionIdAllocator::Release(); }
+  virtual void WillRefresh(mozilla::TimeStamp aTime);
 private:
   typedef nsTObserverArray<nsARefreshObserver*> ObserverArray;
   typedef nsTHashtable<nsISupportsHashKey> RequestTable;
@@ -328,6 +335,8 @@ private:
   nsPresContext *mPresContext; // weak; pres context passed in constructor
                                // and unset in Disconnect
 
+  nsRefPtr<nsRefreshDriver> mRootRefresh;
+
   // The most recently allocated transaction id.
   uint64_t mPendingTransaction;
   // The most recently completed transaction id.