[PAUSED] Add a scope for disallowing style update when calling hasEditableStyle

third_party/WebKit/Source/core/dom/DocumentLifecycle.h

Index: third_party/WebKit/Source/core/dom/DocumentLifecycle.h
diff --git a/third_party/WebKit/Source/core/dom/DocumentLifecycle.h b/third_party/WebKit/Source/core/dom/DocumentLifecycle.h
index 8a05f66132effcf255ec2ebb9ff72cbda8ce650a..170006505f026fa74b722e83bbe8aee029879484 100644
--- a/third_party/WebKit/Source/core/dom/DocumentLifecycle.h
+++ b/third_party/WebKit/Source/core/dom/DocumentLifecycle.h
@@ -150,6 +150,28 @@ class CORE_EXPORT DocumentLifecycle {
     DocumentLifecycle& m_documentLifecycle;
   };
 
+  // This scope should only be used when we need to call hasEditableStyle(), but
+  // the document's style may be dirty and cannot be updated due to some other
+  // blockers. In the long term, we should fix those blockers and remove this
+  // scope.  See crbug.com/667575 for details.
+  class DisallowStyleRecalcScope {
+    STACK_ALLOCATED();
+    DISALLOW_COPY_AND_ASSIGN(DisallowStyleRecalcScope);
+
+   public:
+    explicit DisallowStyleRecalcScope(DocumentLifecycle& documentLifecycle)
+        : m_documentLifecycle(documentLifecycle) {
+      m_documentLifecycle.incrementNoStyleRecalcCount();
+    }
+
+    ~DisallowStyleRecalcScope() {
+      m_documentLifecycle.decrementNoStyleRecalcCount();
+    }
+
+   private:
+    DocumentLifecycle& m_documentLifecycle;
+  };
+
   // Throttling is disabled by default. Instantiating this class allows
   // throttling (e.g., during BeginMainFrame). If a script needs to run inside
   // this scope, DisallowThrottlingScope should be used to let the script
@@ -204,6 +226,10 @@ class CORE_EXPORT DocumentLifecycle {
     m_detachCount--;
   }
 
+  bool styleRecalcDisallowed() const { return m_disallowStyleRecalcCount; }
+  void incrementNoStyleRecalcCount() { ++m_disallowStyleRecalcCount; }
+  void decrementNoStyleRecalcCount() { --m_disallowStyleRecalcCount; }
+
   bool throttlingAllowed() const;
 
  private:
@@ -216,6 +242,7 @@ class CORE_EXPORT DocumentLifecycle {
   LifecycleState m_state;
   int m_detachCount;
   int m_disallowTransitionCount;
+  int m_disallowStyleRecalcCount;
 };
 
 inline bool DocumentLifecycle::stateAllowsTreeMutations() const {