Add CHECK to diagnose unexpected document lifecycle transition.

BUG=825854
R=bokan@chromium.org

Change-Id: Ic7533778665ce8e980b3f269d348aa0448f2bc3f
Reviewed-on: https://chromium-review.googlesource.com/1026529Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Stefan Zager <szager@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553374}

third_party/blink/renderer/core/dom/document_lifecycle.cc

@@ -86,7 +86,10 @@ DocumentLifecycle::DisallowThrottlingScope::~DisallowThrottlingScope() {
 }
 
 DocumentLifecycle::DocumentLifecycle()
-    : state_(kUninitialized), detach_count_(0), disallow_transition_count_(0) {}
+    : state_(kUninitialized),
+      detach_count_(0),
+      disallow_transition_count_(0),
+      check_no_transition_(false) {}
 
 DocumentLifecycle::~DocumentLifecycle() = default;
 
@@ -335,6 +338,7 @@ void DocumentLifecycle::AdvanceTo(LifecycleState next_state) {
       << "Cannot advance document lifecycle from " << StateAsDebugString(state_)
       << " to " << StateAsDebugString(next_state) << ".";
 #endif
+  CHECK(state_ == next_state || !check_no_transition_);
   state_ = next_state;
 }
 
@@ -348,6 +352,7 @@ void DocumentLifecycle::EnsureStateAtMost(LifecycleState state) {
       << "Cannot rewind document lifecycle from " << StateAsDebugString(state_)
       << " to " << StateAsDebugString(state) << ".";
 #endif
+  CHECK(state_ == state || !check_no_transition_);
   state_ = state;
 }
 

third_party/blink/renderer/core/dom/document_lifecycle.h

@@ -35,6 +35,7 @@
 #include "third_party/blink/renderer/core/core_export.h"
 #include "third_party/blink/renderer/platform/wtf/allocator.h"
 #include "third_party/blink/renderer/platform/wtf/assertions.h"
+#include "third_party/blink/renderer/platform/wtf/auto_reset.h"
 
 #if DCHECK_IS_ON()
 #include "third_party/blink/renderer/platform/wtf/forward.h"
@@ -196,6 +197,17 @@ class CORE_EXPORT DocumentLifecycle {
     DocumentLifecycle& document_lifecycle_;
   };
 
+  class CheckNoTransitionScope {
+    STACK_ALLOCATED();
+
+   public:
+    explicit CheckNoTransitionScope(DocumentLifecycle& document_lifecycle)
+        : auto_reset_(&document_lifecycle.check_no_transition_, true) {}
+
+   private:
+    AutoReset<bool> auto_reset_;
+  };
+
   DocumentLifecycle();
   ~DocumentLifecycle();
 
@@ -233,6 +245,7 @@ class CORE_EXPORT DocumentLifecycle {
 #endif
  private:
   friend class PostponeTransitionScope;
+  friend class CheckNoTransitionScope;
 #if DCHECK_IS_ON()
   bool CanAdvanceTo(LifecycleState) const;
   bool CanRewindTo(LifecycleState) const;
@@ -245,6 +258,7 @@ class CORE_EXPORT DocumentLifecycle {
   int detach_count_;
   int disallow_transition_count_;
   bool life_cycle_postponed_;
+  bool check_no_transition_;
   DISALLOW_COPY_AND_ASSIGN(DocumentLifecycle);
 };
 

third_party/blink/renderer/core/frame/local_frame_view.cc

@@ -1078,28 +1078,32 @@ void LocalFrameView::PerformLayout(bool in_subtree_layout) {
   // functions so that a single human could understand what layout() is actually
   // doing.
 
-  if (in_subtree_layout) {
-    if (analyzer_) {
-      analyzer_->Increment(LayoutAnalyzer::kPerformLayoutRootLayoutObjects,
-                           layout_subtree_root_list_.size());
-    }
-    for (auto& root : layout_subtree_root_list_.Ordered()) {
-      if (!root->NeedsLayout())
-        continue;
-      LayoutFromRootObject(*root);
-
-      // We need to ensure that we mark up all layoutObjects up to the
-      // LayoutView for paint invalidation. This simplifies our code as we
-      // just always do a full tree walk.
-      if (LayoutObject* container = root->Container())
-        container->SetMayNeedPaintInvalidation();
+  {
+    // TODO(szager): Remove this after diagnosing crash.
+    DocumentLifecycle::CheckNoTransitionScope check_no_transition(Lifecycle());
+    if (in_subtree_layout) {
+      if (analyzer_) {
+        analyzer_->Increment(LayoutAnalyzer::kPerformLayoutRootLayoutObjects,
+                             layout_subtree_root_list_.size());
+      }
+      for (auto& root : layout_subtree_root_list_.Ordered()) {
+        if (!root->NeedsLayout())
+          continue;
+        LayoutFromRootObject(*root);
+
+        // We need to ensure that we mark up all layoutObjects up to the
+        // LayoutView for paint invalidation. This simplifies our code as we
+        // just always do a full tree walk.
+        if (LayoutObject* container = root->Container())
+          container->SetMayNeedPaintInvalidation();
+      }
+      layout_subtree_root_list_.Clear();
+    } else {
+      if (HasOrthogonalWritingModeRoots() &&
+          !RuntimeEnabledFeatures::LayoutNGEnabled())
+        LayoutOrthogonalWritingModeRoots();
+      GetLayoutView()->UpdateLayout();
     }
-    layout_subtree_root_list_.Clear();
-  } else {
-    if (HasOrthogonalWritingModeRoots() &&
-        !RuntimeEnabledFeatures::LayoutNGEnabled())
-      LayoutOrthogonalWritingModeRoots();
-    GetLayoutView()->UpdateLayout();
   }
 
   frame_->GetDocument()->Fetcher()->UpdateAllImageResourcePriorities();