Add CHECKs to diagnose crash

Bug: 1092673
Change-Id: I088d993addb97e76dd35c6166f5b179008bf50a3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2268880Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Stefan Zager <szager@chromium.org>
Cr-Commit-Position: refs/heads/master@{#782803}

third_party/blink/renderer/core/paint/compositing/graphics_layer_tree_builder.cc

@@ -129,7 +129,8 @@ void GraphicsLayerTreeBuilder::RebuildRecursive(
       DisableCompositingQueryAsserts disabler;
       if (inner_compositor->InCompositingMode()) {
         GraphicsLayer* inner_root_layer = inner_compositor->RootGraphicsLayer();
-        DCHECK(inner_root_layer);
+        // TODO(szager): Change to DCHECK after diagnosing crbug.com/1092673
+        CHECK(inner_root_layer);
         layer_vector_for_children->push_back(inner_root_layer);
       }
       inner_compositor->ClearRootLayerAttachmentDirty();

third_party/blink/renderer/platform/graphics/graphics_layer.cc

@@ -211,6 +211,8 @@ bool GraphicsLayer::SetChildren(const GraphicsLayerVector& new_children) {
 }
 
 void GraphicsLayer::AddChildInternal(GraphicsLayer* child_layer) {
+  // TODO(szager): Remove CHECK after diagnosing crbug.com/1092673
+  CHECK(child_layer);
   DCHECK_NE(child_layer, this);
 
   if (child_layer->Parent())