1 files changed, 19 insertions, 3 deletions
diff --git a/chromium/third_party/blink/renderer/platform/graphics/gpu/dawn_control_client_holder.cc b/chromium/third_party/blink/renderer/platform/graphics/gpu/dawn_control_client_holder.cc
index be5b392fa83..6a6283972e7 100644
--- a/chromium/third_party/blink/renderer/platform/graphics/gpu/dawn_control_client_holder.cc
+++ b/chromium/third_party/blink/renderer/platform/graphics/gpu/dawn_control_client_holder.cc
@@ -17,9 +17,17 @@ scoped_refptr<DawnControlClientHolder> DawnControlClientHolder::Create(
   auto dawn_control_client_holder =
       base::MakeRefCounted<DawnControlClientHolder>(std::move(context_provider),
                                                     std::move(task_runner));
+  // The context lost callback occurs when the client receives
+  // OnGpuControlLostContext. This can happen on fatal errors when the GPU
+  // channel is disconnected: the GPU process crashes, the GPU process fails to
+  // deserialize a message, etc. We mark the context lost, but NOT destroy the
+  // entire WebGraphicsContext3DProvider as that would free services for mapping
+  // shared memory. There may still be outstanding mapped GPUBuffers pointing to
+  // this memory.
   dawn_control_client_holder->context_provider_->ContextProvider()
       ->SetLostContextCallback(WTF::BindRepeating(
-          &DawnControlClientHolder::Destroy, dawn_control_client_holder));
+          &DawnControlClientHolder::MarkContextLost,
+          dawn_control_client_holder->weak_ptr_factory_.GetWeakPtr()));
   return dawn_control_client_holder;
 }
 
@@ -38,7 +46,7 @@ DawnControlClientHolder::DawnControlClientHolder(
 DawnControlClientHolder::~DawnControlClientHolder() = default;
 
 void DawnControlClientHolder::Destroy() {
-  api_channel_->Disconnect();
+  MarkContextLost();
 
   // Destroy the WebGPU context.
   // This ensures that GPU resources are eagerly reclaimed.
@@ -68,8 +76,16 @@ DawnControlClientHolder::GetContextProviderWeakPtr() const {
   return context_provider_->GetWeakPtr();
 }
 
+void DawnControlClientHolder::MarkContextLost() {
+  if (context_lost_) {
+    return;
+  }
+  api_channel_->Disconnect();
+  context_lost_ = true;
+}
+
 bool DawnControlClientHolder::IsContextLost() const {
-  return !context_provider_;
+  return context_lost_;
 }
 
 std::unique_ptr<RecyclableCanvasResource>