Bug 1315974 - When creating the widget layer manager, don't assume it will always be a ClientLayerManager. r=mattwoodrow

MozReview-Commit-ID: 8r037jdHJ0E

--HG--
extra : rebase_source : 5f0e406ea6eb497b72f40054ba50cf64a6bd7dfb

dom/ipc/TabChild.cpp

@@ -2413,8 +2413,9 @@ TabChild::RecvSetDocShellIsActive(const bool& aIsActive,
   // We send the current layer observer epoch to the compositor so that
   // TabParent knows whether a layer update notification corresponds to the
   // latest SetDocShellIsActive request that was made.
-  ClientLayerManager *manager = mPuppetWidget->GetLayerManager()->AsClientLayerManager();
-  manager->SetLayerObserverEpoch(aLayerObserverEpoch);
+  if (ClientLayerManager* clm = mPuppetWidget->GetLayerManager()->AsClientLayerManager()) {
+    clm->SetLayerObserverEpoch(aLayerObserverEpoch);
+  }
 
   // docshell is consider prerendered only if not active yet
   mIsPrerendered &= !aIsActive;
@@ -2588,34 +2589,40 @@ TabChild::InitRenderingState(const TextureFactoryIdentifier& aTextureFactoryIden
       PRenderFrameChild::Send__delete__(remoteFrame);
       return false;
     }
-    nsTArray<LayersBackend> backends;
-    backends.AppendElement(mTextureFactoryIdentifier.mParentBackend);
-    bool success;
-    PLayerTransactionChild* shadowManager =
-        compositorChild->SendPLayerTransactionConstructor(backends,
-                                                          aLayersId, &mTextureFactoryIdentifier, &success);
-    if (!success) {
-      NS_WARNING("failed to properly allocate layer transaction");
-      PRenderFrameChild::Send__delete__(remoteFrame);
-      return false;
-    }
-
-    if (!shadowManager) {
-      NS_WARNING("failed to construct LayersChild");
-      // This results in |remoteFrame| being deleted.
-      PRenderFrameChild::Send__delete__(remoteFrame);
-      return false;
-    }
 
     ShadowLayerForwarder* lf =
         mPuppetWidget->GetLayerManager(
-            shadowManager, mTextureFactoryIdentifier.mParentBackend)
+            nullptr, mTextureFactoryIdentifier.mParentBackend)
                 ->AsShadowForwarder();
-    MOZ_ASSERT(lf && lf->HasShadowManager(),
-               "PuppetWidget should have shadow manager");
-    lf->IdentifyTextureHost(mTextureFactoryIdentifier);
-    ImageBridgeChild::IdentifyCompositorTextureHost(mTextureFactoryIdentifier);
-    gfx::VRManagerChild::IdentifyTextureHost(mTextureFactoryIdentifier);
+    // As long as we are creating a ClientLayerManager for the puppet widget,
+    // lf must be non-null here.
+    MOZ_ASSERT(lf);
+
+    if (lf) {
+      nsTArray<LayersBackend> backends;
+      backends.AppendElement(mTextureFactoryIdentifier.mParentBackend);
+      bool success;
+      PLayerTransactionChild* shadowManager =
+          compositorChild->SendPLayerTransactionConstructor(backends,
+                                                            aLayersId, &mTextureFactoryIdentifier, &success);
+      if (!success) {
+        NS_WARNING("failed to properly allocate layer transaction");
+        PRenderFrameChild::Send__delete__(remoteFrame);
+        return false;
+      }
+
+      if (!shadowManager) {
+        NS_WARNING("failed to construct LayersChild");
+        // This results in |remoteFrame| being deleted.
+        PRenderFrameChild::Send__delete__(remoteFrame);
+        return false;
+      }
+
+      lf->SetShadowManager(shadowManager);
+      lf->IdentifyTextureHost(mTextureFactoryIdentifier);
+      ImageBridgeChild::IdentifyCompositorTextureHost(mTextureFactoryIdentifier);
+      gfx::VRManagerChild::IdentifyTextureHost(mTextureFactoryIdentifier);
+    }
 
     mRemoteFrame = remoteFrame;
     if (aLayersId != 0) {
@@ -2997,6 +3004,7 @@ TabChild::CompositorUpdated(const TextureFactoryIdentifier& aNewIdentifier)
 
   RefPtr<LayerManager> lm = mPuppetWidget->GetLayerManager();
   ClientLayerManager* clm = lm->AsClientLayerManager();
+  MOZ_ASSERT(clm);
 
   mTextureFactoryIdentifier = aNewIdentifier;
   clm->UpdateTextureFactoryIdentifier(aNewIdentifier);

widget/PuppetWidget.cpp

@@ -584,7 +584,7 @@ PuppetWidget::GetLayerManager(PLayerTransactionChild* aShadowManager,
     mLayerManager = new ClientLayerManager(this);
   }
   ShadowLayerForwarder* lf = mLayerManager->AsShadowForwarder();
-  if (!lf->HasShadowManager() && aShadowManager) {
+  if (lf && !lf->HasShadowManager() && aShadowManager) {
     lf->SetShadowManager(aShadowManager);
   }
   return mLayerManager;
@@ -594,7 +594,9 @@ LayerManager*
 PuppetWidget::RecreateLayerManager(PLayerTransactionChild* aShadowManager)
 {
   mLayerManager = new ClientLayerManager(this);
-  mLayerManager->AsShadowForwarder()->SetShadowManager(aShadowManager);
+  if (ShadowLayerForwarder* lf = mLayerManager->AsShadowForwarder()) {
+    lf->SetShadowManager(aShadowManager);
+  }
   return mLayerManager;
 }
 

widget/nsBaseWidget.cpp

@@ -1331,35 +1331,42 @@ void nsBaseWidget::CreateCompositor(int aWidth, int aHeight)
     mInitialZoomConstraints.reset();
   }
 
-  TextureFactoryIdentifier textureFactoryIdentifier;
-  PLayerTransactionChild* shadowManager = nullptr;
-
-  nsTArray<LayersBackend> backendHints;
-  gfxPlatform::GetPlatform()->GetCompositorBackends(ComputeShouldAccelerate(), backendHints);
-
-  bool success = false;
-  if (!backendHints.IsEmpty()) {
-    shadowManager = mCompositorBridgeChild->SendPLayerTransactionConstructor(
-      backendHints, 0, &textureFactoryIdentifier, &success);
-  }
-
   ShadowLayerForwarder* lf = lm->AsShadowForwarder();
+  // As long as we are creating a ClientLayerManager above lf must be non-null.
+  MOZ_ASSERT(lf);
 
-  if (!success || !lf) {
-    NS_WARNING("Failed to create an OMT compositor.");
-    DestroyCompositor();
-    mLayerManager = nullptr;
-    return;
+  if (lf) {
+    TextureFactoryIdentifier textureFactoryIdentifier;
+    PLayerTransactionChild* shadowManager = nullptr;
+
+    nsTArray<LayersBackend> backendHints;
+    gfxPlatform::GetPlatform()->GetCompositorBackends(ComputeShouldAccelerate(), backendHints);
+
+    bool success = false;
+    if (!backendHints.IsEmpty()) {
+      shadowManager = mCompositorBridgeChild->SendPLayerTransactionConstructor(
+        backendHints, 0, &textureFactoryIdentifier, &success);
+    }
+
+    if (!success) {
+      NS_WARNING("Failed to create an OMT compositor.");
+      DestroyCompositor();
+      mLayerManager = nullptr;
+      return;
+    }
+
+    lf->SetShadowManager(shadowManager);
+    if (ClientLayerManager* clm = lm->AsClientLayerManager()) {
+      clm->UpdateTextureFactoryIdentifier(textureFactoryIdentifier);
+    }
+    // Some popup or transparent widgets may use a different backend than the
+    // compositors used with ImageBridge and VR (and more generally web content).
+    if (WidgetTypeSupportsAcceleration()) {
+      ImageBridgeChild::IdentifyCompositorTextureHost(textureFactoryIdentifier);
+      gfx::VRManagerChild::IdentifyTextureHost(textureFactoryIdentifier);
+    }
   }
 
-  lf->SetShadowManager(shadowManager);
-  lm->UpdateTextureFactoryIdentifier(textureFactoryIdentifier);
-  // Some popup or transparent widgets may use a different backend than the
-  // compositors used with ImageBridge and VR (and more generally web content).
-  if (WidgetTypeSupportsAcceleration()) {
-    ImageBridgeChild::IdentifyCompositorTextureHost(textureFactoryIdentifier);
-    gfx::VRManagerChild::IdentifyTextureHost(textureFactoryIdentifier);
-  }
   WindowUsesOMTC();
 
   mLayerManager = lm.forget();