From bce40231eacba55a6d0dbdf222ff482b5b1fbc71 Mon Sep 17 00:00:00 2001
From: sotaro <sotaro.ikeda.g@gmail.com>
Date: Fri, 3 Nov 2017 16:38:34 +0900
Subject: [PATCH] Bug 1390741 - Use BasicCompositor if widget type does not
 support acceleration r=aosmond,kats

---
 dom/ipc/TabChild.cpp                      | 10 +++++++++-
 dom/ipc/TabChild.h                        |  1 +
 gfx/layers/ipc/CompositorBridgeParent.cpp |  1 +
 gfx/layers/ipc/LayerTransactionParent.cpp |  4 ++++
 gfx/layers/wr/WebRenderBridgeParent.cpp   | 13 ++++++++++++-
 widget/PuppetWidget.cpp                   |  2 +-
 widget/nsBaseWidget.cpp                   | 11 ++++-------
 7 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/dom/ipc/TabChild.cpp b/dom/ipc/TabChild.cpp
index 9d091474ed47..2cd11e8c97c5 100644
--- a/dom/ipc/TabChild.cpp
+++ b/dom/ipc/TabChild.cpp
@@ -465,6 +465,14 @@ TabChild::TabChild(nsIContentChild* aManager,
   }
 }
 
+const CompositorOptions&
+TabChild::GetCompositorOptions() const
+{
+  // If you're calling this before mCompositorOptions is set, well.. don't.
+  MOZ_ASSERT(mCompositorOptions);
+  return mCompositorOptions.ref();
+}
+
 bool
 TabChild::AsyncPanZoomEnabled() const
 {
@@ -2950,7 +2958,7 @@ TabChild::CreateRemoteLayerManager(mozilla::layers::PCompositorBridgeChild* aCom
   MOZ_ASSERT(aCompositorChild);
 
   bool success = false;
-  if (gfxVars::UseWebRender()) {
+  if (mCompositorOptions->UseWebRender()) {
     success = mPuppetWidget->CreateRemoteLayerManager([&] (LayerManager* aLayerManager) -> bool {
       MOZ_ASSERT(aLayerManager->AsWebRenderLayerManager());
       return aLayerManager->AsWebRenderLayerManager()->Initialize(aCompositorChild,
diff --git a/dom/ipc/TabChild.h b/dom/ipc/TabChild.h
index efaca3d8d0ee..479393a4f719 100644
--- a/dom/ipc/TabChild.h
+++ b/dom/ipc/TabChild.h
@@ -685,6 +685,7 @@ public:
     return mParentIsActive;
   }
 
+  const mozilla::layers::CompositorOptions& GetCompositorOptions() const;
   bool AsyncPanZoomEnabled() const;
 
   virtual ScreenIntSize GetInnerSize() override;
diff --git a/gfx/layers/ipc/CompositorBridgeParent.cpp b/gfx/layers/ipc/CompositorBridgeParent.cpp
index d6e779ab9416..3eca62d62c67 100644
--- a/gfx/layers/ipc/CompositorBridgeParent.cpp
+++ b/gfx/layers/ipc/CompositorBridgeParent.cpp
@@ -1477,6 +1477,7 @@ CompositorBridgeParent::NewCompositor(const nsTArray<LayersBackend>& aBackendHin
 #endif
     }
     nsCString failureReason;
+    MOZ_ASSERT(!gfxVars::UseWebRender() || aBackendHints[i] == LayersBackend::LAYERS_BASIC);
     if (compositor && compositor->Initialize(&failureReason)) {
       if (failureReason.IsEmpty()){
         failureReason = "SUCCESS";
diff --git a/gfx/layers/ipc/LayerTransactionParent.cpp b/gfx/layers/ipc/LayerTransactionParent.cpp
index bf2f4124f599..f41791eeec85 100644
--- a/gfx/layers/ipc/LayerTransactionParent.cpp
+++ b/gfx/layers/ipc/LayerTransactionParent.cpp
@@ -877,6 +877,10 @@ LayerTransactionParent::Attach(Layer* aLayer,
   TextureSourceProvider* provider =
     static_cast<HostLayerManager*>(aLayer->Manager())->GetTextureSourceProvider();
 
+  MOZ_ASSERT(!aCompositable->AsWebRenderImageHost());
+  if (aCompositable->AsWebRenderImageHost()) {
+    gfxCriticalNote << "Use WebRenderImageHost at LayerTransactionParent.";
+  }
   if (!layer->SetCompositableHost(aCompositable)) {
     // not all layer types accept a compositable, see bug 967824
     return false;
diff --git a/gfx/layers/wr/WebRenderBridgeParent.cpp b/gfx/layers/wr/WebRenderBridgeParent.cpp
index a957b9996278..d3896495bdf9 100644
--- a/gfx/layers/wr/WebRenderBridgeParent.cpp
+++ b/gfx/layers/wr/WebRenderBridgeParent.cpp
@@ -800,8 +800,13 @@ WebRenderBridgeParent::RecvAddPipelineIdForCompositable(const wr::PipelineId& aP
   if (!host) {
     return IPC_FAIL_NO_REASON(this);
   }
-  MOZ_ASSERT(host->AsWebRenderImageHost());
+
   WebRenderImageHost* wrHost = host->AsWebRenderImageHost();
+  MOZ_ASSERT(wrHost);
+  if (!wrHost) {
+    gfxCriticalNote << "Incompatible CompositableHost at WebRenderBridgeParent.";
+  }
+
   if (!wrHost) {
     return IPC_OK();
   }
@@ -843,6 +848,12 @@ WebRenderBridgeParent::RecvAddExternalImageIdForCompositable(const ExternalImage
 
   RefPtr<CompositableHost> host = FindCompositable(aHandle);
   WebRenderImageHost* wrHost = host->AsWebRenderImageHost();
+
+  MOZ_ASSERT(wrHost);
+  if (!wrHost) {
+    gfxCriticalNote << "Incompatible CompositableHost for external image at WebRenderBridgeParent.";
+  }
+
   if (!wrHost) {
     return IPC_OK();
   }
diff --git a/widget/PuppetWidget.cpp b/widget/PuppetWidget.cpp
index 73fbd307a36e..0784e750978c 100644
--- a/widget/PuppetWidget.cpp
+++ b/widget/PuppetWidget.cpp
@@ -612,7 +612,7 @@ PuppetWidget::CreateRemoteLayerManager(const std::function<bool(LayerManager*)>&
 {
   RefPtr<LayerManager> lm;
   MOZ_ASSERT(mTabChild);
-  if (gfxVars::UseWebRender()) {
+  if (mTabChild->GetCompositorOptions().UseWebRender()) {
     lm = new WebRenderLayerManager(this);
   } else {
     lm = new ClientLayerManager(this);
diff --git a/widget/nsBaseWidget.cpp b/widget/nsBaseWidget.cpp
index 3ffa16d17daa..c0694714c69d 100644
--- a/widget/nsBaseWidget.cpp
+++ b/widget/nsBaseWidget.cpp
@@ -1255,11 +1255,10 @@ nsBaseWidget::CreateCompositorSession(int aWidth,
   do {
     CreateCompositorVsyncDispatcher();
 
-    bool enableWR = gfx::gfxVars::UseWebRender();
-    if (enableWR && !WidgetTypeSupportsAcceleration()) {
-      // fall back to basic
-      break;
-    }
+    // If widget type does not supports acceleration, we use ClientLayerManager
+    // even when gfxVars::UseWebRender() is true. WebRender could coexist only
+    // with BasicCompositor.
+    bool enableWR = gfx::gfxVars::UseWebRender() && WidgetTypeSupportsAcceleration();
     bool enableAPZ = UseAPZ();
     CompositorOptions options(enableAPZ, enableWR);
 
@@ -1303,8 +1302,6 @@ nsBaseWidget::CreateCompositorSession(int aWidth,
       return lm.forget();
     }
   } while (true);
-
-  return nullptr;
 }
 
 void nsBaseWidget::CreateCompositor(int aWidth, int aHeight)