Bug 1137944 - Add support for hiding plugin windows during async dom scroll operations managed in the content process. r=roc

layout/generic/nsGfxScrollFrame.cpp

@@ -45,6 +45,7 @@
 #include "nsSMILKeySpline.h"
 #include "nsSubDocumentFrame.h"
 #include "nsSVGOuterSVGFrame.h"
+#include "nsIObjectLoadingContent.h"
 #include "mozilla/Attributes.h"
 #include "ScrollbarActivity.h"
 #include "nsRefreshDriver.h"
@@ -57,6 +58,7 @@
 #include "gfxPrefs.h"
 #include "AsyncScrollBase.h"
 #include "UnitTransforms.h"
+#include "nsPluginFrame.h"
 #include <mozilla/layers/AxisPhysicsModel.h>
 #include <mozilla/layers/AxisPhysicsMSDModel.h>
 #include <algorithm>
@@ -1852,6 +1854,7 @@ ScrollFrameHelper::ScrollFrameHelper(nsContainerFrame* aOuter,
   , mTransformingByAPZ(false)
   , mZoomableByAPZ(false)
   , mVelocityQueue(aOuter->PresContext())
+  , mAsyncScrollEvent(END)
 {
   if (LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars) != 0) {
     mScrollbarActivity = new ScrollbarActivity(do_QueryFrame(aOuter));
@@ -1958,6 +1961,8 @@ ScrollFrameHelper::AsyncScrollCallback(ScrollFrameHelper* aInstance,
 void
 ScrollFrameHelper::CompleteAsyncScroll(const nsRect &aRange, nsIAtom* aOrigin)
 {
+  NotifyPluginFrames(END);
+
   // Apply desired destination range since this is the last step of scrolling.
   mAsyncSmoothMSDScroll = nullptr;
   mAsyncScroll = nullptr;
@@ -1971,6 +1976,38 @@ ScrollFrameHelper::CompleteAsyncScroll(const nsRect &aRange, nsIAtom* aOrigin)
   mDestination = GetScrollPosition();
 }
 
+#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
+static void
+NotifyPluginFramesCallback(nsISupports* aSupports, void* aFlag)
+{
+  nsCOMPtr<nsIContent> content = do_QueryInterface(aSupports);
+  if (content) {
+    nsIFrame *frame = content->GetPrimaryFrame();
+    if (frame) {
+      nsPluginFrame* plugin = do_QueryFrame(frame);
+      if (plugin) {
+        plugin->SetScrollVisibility(aFlag != nullptr);
+      }
+    }
+  }
+}
+#endif
+
+void
+ScrollFrameHelper::NotifyPluginFrames(AsyncScrollEventType aEvent)
+{
+#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
+  if (XRE_IsContentProcess()) {
+    if (aEvent != mAsyncScrollEvent) {
+      nsPresContext* presContext = mOuter->PresContext();
+      presContext->Document()->EnumerateActivityObservers(NotifyPluginFramesCallback,
+                                                          (void*)(aEvent == BEGIN));
+      mAsyncScrollEvent = aEvent;
+    }
+  }
+#endif
+}
+
 void
 ScrollFrameHelper::ScrollToCSSPixels(const CSSIntPoint& aScrollPosition,
                                      nsIScrollableFrame::ScrollMode aMode)
@@ -2125,6 +2162,7 @@ ScrollFrameHelper::ScrollToWithOrigin(nsPoint aScrollPosition,
   mAsyncScroll->mIsSmoothScroll = isSmoothScroll;
 
   if (isSmoothScroll) {
+    NotifyPluginFrames(BEGIN);
     mAsyncScroll->InitSmoothScroll(now, mDestination, aOrigin, range, currentVelocity);
   } else {
     mAsyncScroll->Init(range);

layout/generic/nsGfxScrollFrame.h

@@ -558,6 +558,14 @@ protected:
 
   void CompleteAsyncScroll(const nsRect &aRange, nsIAtom* aOrigin = nullptr);
 
+  /*
+   * Helper that notifies plugins about async smooth scroll operations managed
+   * by nsGfxScrollFrame.
+   */
+  enum AsyncScrollEventType { BEGIN, END };
+  void NotifyPluginFrames(AsyncScrollEventType aEvent);
+  AsyncScrollEventType mAsyncScrollEvent;
+
   static void EnsureImageVisPrefsCached();
   static bool sImageVisPrefsCached;
   // The number of scrollports wide/high to expand when looking for images.

layout/generic/nsPluginFrame.cpp

@@ -157,6 +157,7 @@ nsPluginFrame::nsPluginFrame(nsStyleContext* aContext)
   : nsPluginFrameSuper(aContext)
   , mInstanceOwner(nullptr)
   , mReflowCallbackPosted(false)
+  , mIsHiddenDueToScroll(false)
 {
   MOZ_LOG(GetObjectFrameLog(), LogLevel::Debug,
          ("Created new nsPluginFrame %p\n", this));
@@ -764,6 +765,23 @@ nsPluginFrame::IsHidden(bool aCheckVisibilityStyle) const
   return false;
 }
 
+// Clips windowed plugin frames during remote content scroll operations managed
+// by nsGfxScrollFrame.
+void
+nsPluginFrame::SetScrollVisibility(bool aState)
+{
+  // Limit this setting to windowed plugins by checking if we have a widget
+  if (mWidget) {
+    bool changed = mIsHiddenDueToScroll != aState;
+    mIsHiddenDueToScroll = aState;
+    // Force a paint so plugin window visibility gets flushed via
+    // the compositor.
+    if (changed) {
+      SchedulePaint();
+    }
+  }
+}
+
 mozilla::LayoutDeviceIntPoint
 nsPluginFrame::GetRemoteTabChromeOffset()
 {
@@ -1098,6 +1116,11 @@ nsPluginFrame::DidSetWidgetGeometry()
 bool
 nsPluginFrame::IsOpaque() const
 {
+  // Insure underlying content gets painted when we clip windowed plugins
+  // during remote content scroll operations managed by nsGfxScrollFrame.
+  if (mIsHiddenDueToScroll) {
+    return false;
+  }
 #if defined(XP_MACOSX)
   return false;
 #elif defined(MOZ_WIDGET_ANDROID)
@@ -1143,6 +1166,12 @@ nsPluginFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 const nsRect&           aDirtyRect,
                                 const nsDisplayListSet& aLists)
 {
+  // Clip windowed plugin frames from the list during remote content scroll
+  // operations managed by nsGfxScrollFrame.
+  if (mIsHiddenDueToScroll) {
+    return;
+  }
+
   // XXX why are we painting collapsed object frames?
   if (!IsVisibleOrCollapsedForPainting(aBuilder))
     return;

layout/generic/nsPluginFrame.h

@@ -24,6 +24,7 @@
 #undef GetClassName
 #undef GetBinaryType
 #undef RemoveDirectory
+#undef LoadIcon
 #endif
 
 class nsPresContext;
@@ -199,6 +200,11 @@ public:
 
   void SetInstanceOwner(nsPluginInstanceOwner* aOwner);
 
+  /**
+   * Helper for hiding windowed plugins during non-apz scroll operations.
+   */
+  void SetScrollVisibility(bool aState);
+
 protected:
   explicit nsPluginFrame(nsStyleContext* aContext);
   virtual ~nsPluginFrame();
@@ -302,6 +308,10 @@ private:
   // This is only non-null while we have a plugin registered for geometry
   // updates.
   nsRefPtr<nsRootPresContext> mRootPresContextRegisteredWith;
+
+  // Tracks windowed plugin visibility during scroll operations. See
+  // SetScrollVisibility.
+  bool mIsHiddenDueToScroll;
 };
 
 class nsDisplayPlugin : public nsDisplayItem {