From e7afee4bf1f6e70ceea174bcd49b074b9feeb112 Mon Sep 17 00:00:00 2001
From: Brad Werth <bwerth@mozilla.com>
Date: Wed, 7 Sep 2022 18:51:12 +0000
Subject: [PATCH] Bug 1781122 Part 3: Make macOS video layers prevent capture
 when TextureHost is DRM. r=mstange

Differential Revision: https://phabricator.services.mozilla.com/D155297
---
 gfx/layers/NativeLayerCA.h  |  4 +++-
 gfx/layers/NativeLayerCA.mm | 31 +++++++++++++++++++++++--------
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/gfx/layers/NativeLayerCA.h b/gfx/layers/NativeLayerCA.h
index 1ab21b675e83..a43b8ccdda5d 100644
--- a/gfx/layers/NativeLayerCA.h
+++ b/gfx/layers/NativeLayerCA.h
@@ -362,7 +362,7 @@ class NativeLayerCA : public NativeLayer {
                       gfx::SamplingFilter aSamplingFilter,
                       bool aSpecializeVideo,
                       CFTypeRefPtr<IOSurfaceRef> aFrontSurface,
-                      CFTypeRefPtr<CGColorRef> aColor);
+                      CFTypeRefPtr<CGColorRef> aColor, bool aIsDRM);
 
     // Return whether any aspects of this layer representation have been mutated
     // since the last call to ApplyChanges, i.e. whether ApplyChanges needs to
@@ -390,6 +390,7 @@ class NativeLayerCA : public NativeLayer {
     bool mMutatedFrontSurface : 1;
     bool mMutatedSamplingFilter : 1;
     bool mMutatedSpecializeVideo : 1;
+    bool mMutatedIsDRM : 1;
   };
 
   Representation& GetRepresentation(WhichRepresentation aRepresentation);
@@ -466,6 +467,7 @@ class NativeLayerCA : public NativeLayer {
   bool mRootWindowIsFullscreen = false;
   bool mSpecializeVideo = false;
   bool mHasExtent = false;
+  bool mIsDRM = false;
 };
 
 }  // namespace layers
diff --git a/gfx/layers/NativeLayerCA.mm b/gfx/layers/NativeLayerCA.mm
index 14b2cac4ef40..125f71e8ffd9 100644
--- a/gfx/layers/NativeLayerCA.mm
+++ b/gfx/layers/NativeLayerCA.mm
@@ -823,11 +823,16 @@ void NativeLayerCA::AttachExternalImage(wr::RenderTextureHost* aExternalImage) {
   mSpecializeVideo = ShouldSpecializeVideo(lock);
   bool changedSpecializeVideo = (mSpecializeVideo != oldSpecializeVideo);
 
+  bool oldIsDRM = mIsDRM;
+  mIsDRM = aExternalImage->IsFromDRMSource();
+  bool changedIsDRM = (mIsDRM != oldIsDRM);
+
   ForAllRepresentations([&](Representation& r) {
     r.mMutatedFrontSurface = true;
     r.mMutatedDisplayRect |= changedSizeAndDisplayRect;
     r.mMutatedSize |= changedSizeAndDisplayRect;
     r.mMutatedSpecializeVideo |= changedSpecializeVideo;
+    r.mMutatedIsDRM |= changedIsDRM;
   });
 }
 
@@ -852,12 +857,14 @@ bool NativeLayerCA::ShouldSpecializeVideo(const MutexAutoLock& aProofOfLock) {
     return false;
   }
 
-  // Beyond this point, we need to know about the format of the video.
-
   MOZ_ASSERT(mTextureHost);
-  if (!mTextureHost) {
-    return false;
+
+  // DRM video must use a specialized video layer.
+  if (mTextureHost->IsFromDRMSource()) {
+    return true;
   }
+
+  // Beyond this point, we need to know about the format of the video.
   MacIOSurface* macIOSurface = mTextureHost->GetSurface();
   if (macIOSurface->GetYUVColorSpace() == gfx::YUVColorSpace::BT2020) {
     // BT2020 is a signifier of HDR color space, whether or not the bit depth
@@ -1120,7 +1127,8 @@ NativeLayerCA::Representation::Representation()
       mMutatedSurfaceIsFlipped(true),
       mMutatedFrontSurface(true),
       mMutatedSamplingFilter(true),
-      mMutatedSpecializeVideo(true) {}
+      mMutatedSpecializeVideo(true),
+      mMutatedIsDRM(true) {}
 
 NativeLayerCA::Representation::~Representation() {
   [mContentCALayer release];
@@ -1334,7 +1342,7 @@ bool NativeLayerCA::ApplyChanges(WhichRepresentation aRepresentation,
   return GetRepresentation(aRepresentation)
       .ApplyChanges(aUpdate, mSize, mIsOpaque, mPosition, mTransform, mDisplayRect, mClipRect,
                     mBackingScale, mSurfaceIsFlipped, mSamplingFilter, mSpecializeVideo, surface,
-                    mColor);
+                    mColor, mIsDRM);
 }
 
 CALayer* NativeLayerCA::UnderlyingCALayer(WhichRepresentation aRepresentation) {
@@ -1512,7 +1520,7 @@ bool NativeLayerCA::Representation::ApplyChanges(
     const IntPoint& aPosition, const Matrix4x4& aTransform, const IntRect& aDisplayRect,
     const Maybe<IntRect>& aClipRect, float aBackingScale, bool aSurfaceIsFlipped,
     gfx::SamplingFilter aSamplingFilter, bool aSpecializeVideo,
-    CFTypeRefPtr<IOSurfaceRef> aFrontSurface, CFTypeRefPtr<CGColorRef> aColor) {
+    CFTypeRefPtr<IOSurfaceRef> aFrontSurface, CFTypeRefPtr<CGColorRef> aColor, bool aIsDRM) {
   // If we have an OnlyVideo update, handle it and early exit.
   if (aUpdate == UpdateType::OnlyVideo) {
     // If we don't have any updates to do, exit early with success. This is
@@ -1602,6 +1610,12 @@ bool NativeLayerCA::Representation::ApplyChanges(
     }
   }
 
+  if (@available(macOS 10.15, iOS 13.0, *)) {
+    if (aSpecializeVideo && mMutatedIsDRM) {
+      ((AVSampleBufferDisplayLayer*)mContentCALayer).preventsCapture = aIsDRM;
+    }
+  }
+
   bool shouldTintOpaqueness = StaticPrefs::gfx_core_animation_tint_opaque();
   if (shouldTintOpaqueness && !mOpaquenessTintLayer) {
     mOpaquenessTintLayer = [[CALayer layer] retain];
@@ -1748,6 +1762,7 @@ bool NativeLayerCA::Representation::ApplyChanges(
   mMutatedFrontSurface = false;
   mMutatedSamplingFilter = false;
   mMutatedSpecializeVideo = false;
+  mMutatedIsDRM = false;
 
   return true;
 }
@@ -1761,7 +1776,7 @@ NativeLayerCA::UpdateType NativeLayerCA::Representation::HasUpdate(bool aIsVideo
   // if we can attempt an OnlyVideo update.
   if (mMutatedPosition || mMutatedTransform || mMutatedDisplayRect || mMutatedClipRect ||
       mMutatedBackingScale || mMutatedSize || mMutatedSurfaceIsFlipped || mMutatedSamplingFilter ||
-      mMutatedSpecializeVideo) {
+      mMutatedSpecializeVideo || mMutatedIsDRM) {
     return UpdateType::All;
   }