Bug 1690857 - Add diagnostic assert to ensure we aren't using stale blob keys in the compositor process. r=jrmuizel

Similar to bug 1690821 in the content process, this adds an assert in
the other side in case of a race condition.

Differential Revision: https://phabricator.services.mozilla.com/D104086

gfx/layers/wr/WebRenderBridgeParent.cpp

@@ -518,6 +518,8 @@ bool WebRenderBridgeParent::UpdateResources(
       }
       case OpUpdateResource::TOpAddBlobImage: {
         const auto& op = cmd.get_OpAddBlobImage();
+        MOZ_DIAGNOSTIC_ASSERT(MatchesNamespace(op.key()),
+                              "stale blob key for add!");
         wr::Vec<uint8_t> bytes;
         if (!reader.Read(op.bytes(), bytes)) {
           gfxCriticalNote << "TOpAddBlobImage failed";
@@ -529,6 +531,8 @@ bool WebRenderBridgeParent::UpdateResources(
       }
       case OpUpdateResource::TOpUpdateBlobImage: {
         const auto& op = cmd.get_OpUpdateBlobImage();
+        MOZ_DIAGNOSTIC_ASSERT(MatchesNamespace(op.key()),
+                              "stale blob key for update!");
         wr::Vec<uint8_t> bytes;
         if (!reader.Read(op.bytes(), bytes)) {
           gfxCriticalNote << "TOpUpdateBlobImage failed";
@@ -541,6 +545,8 @@ bool WebRenderBridgeParent::UpdateResources(
       }
       case OpUpdateResource::TOpSetBlobImageVisibleArea: {
         const auto& op = cmd.get_OpSetBlobImageVisibleArea();
+        MOZ_DIAGNOSTIC_ASSERT(MatchesNamespace(op.key()),
+                              "stale blob key for visible area!");
         aUpdates.SetBlobImageVisibleArea(op.key(),
                                          wr::ToDeviceIntRect(op.area()));
         break;

gfx/layers/wr/WebRenderBridgeParent.h

@@ -220,6 +220,14 @@ class WebRenderBridgeParent final : public PWebRenderBridgeParent,
   wr::Epoch GetCurrentEpoch() const { return mWrEpoch; }
   wr::IdNamespace GetIdNamespace() { return mIdNamespace; }
 
+  bool MatchesNamespace(const wr::ImageKey& aImageKey) const {
+    return aImageKey.mNamespace == mIdNamespace;
+  }
+
+  bool MatchesNamespace(const wr::BlobImageKey& aBlobKey) const {
+    return MatchesNamespace(aBlobKey._0);
+  }
+
   void FlushRendering(bool aWaitForPresent = true);
 
   /**