Bug 1622360 - Stop storing unused render root in AsyncImagePipeline. r=jrmuizel

Depends on D74847

Differential Revision: https://phabricator.services.mozilla.com/D74848

gfx/layers/wr/AsyncImagePipelineManager.cpp

@@ -30,7 +30,6 @@ AsyncImagePipelineManager::ForwardingExternalImage::~ForwardingExternalImage() {
 
 AsyncImagePipelineManager::AsyncImagePipeline::AsyncImagePipeline()
     : mInitialised(false),
-      mRenderRoot(wr::RenderRoot::Default),
       mIsChanged(false),
       mUseExternalImage(false),
       mFilter(wr::ImageRendering::Auto),
@@ -134,8 +133,7 @@ WebRenderBridgeParent* AsyncImagePipelineManager::GetWrBridge(
 }
 
 void AsyncImagePipelineManager::AddAsyncImagePipeline(
-    const wr::PipelineId& aPipelineId, WebRenderImageHost* aImageHost,
-    wr::RenderRoot aRenderRoot) {
+    const wr::PipelineId& aPipelineId, WebRenderImageHost* aImageHost) {
   if (mDestroyed) {
     return;
   }
@@ -144,7 +142,6 @@ void AsyncImagePipelineManager::AddAsyncImagePipeline(
 
   MOZ_ASSERT(!mAsyncImagePipelines.Get(id));
   AsyncImagePipeline* holder = new AsyncImagePipeline();
-  holder->mRenderRoot = aRenderRoot;
   holder->mImageHost = aImageHost;
   mAsyncImagePipelines.Put(id, holder);
   AddPipeline(aPipelineId, /* aWrBridge */ nullptr);

gfx/layers/wr/AsyncImagePipelineManager.h

@@ -89,8 +89,7 @@ class AsyncImagePipelineManager final {
   TimeStamp GetCompositeUntilTime() const { return mCompositeUntilTime; }
 
   void AddAsyncImagePipeline(const wr::PipelineId& aPipelineId,
-                             WebRenderImageHost* aImageHost,
-                             wr::RenderRoot aRenderRoot);
+                             WebRenderImageHost* aImageHost);
   void RemoveAsyncImagePipeline(const wr::PipelineId& aPipelineId,
                                 wr::TransactionBuilder& aTxn);
 
@@ -189,7 +188,6 @@ class AsyncImagePipelineManager final {
     }
 
     bool mInitialised;
-    wr::RenderRoot mRenderRoot;
     bool mIsChanged;
     bool mUseExternalImage;
     LayoutDeviceRect mScBounds;

gfx/layers/wr/WebRenderBridgeParent.cpp

@@ -1903,8 +1903,7 @@ void WebRenderBridgeParent::AddPipelineIdForCompositable(
 
   wrHost->SetWrBridge(aPipelineId, this);
   mAsyncCompositables.emplace(wr::AsUint64(aPipelineId), wrHost);
-  mAsyncImageManager->AddAsyncImagePipeline(aPipelineId, wrHost,
-                                            RenderRootForExternal(aRenderRoot));
+  mAsyncImageManager->AddAsyncImagePipeline(aPipelineId, wrHost);
 
   // If this is being called from WebRenderBridgeParent::RecvSetDisplayList,
   // then aTxn might contain a display list that references pipelines that