Properly suspend HTMLDocumentParser

Source/core/dom/ExecutionContext.cpp

Index: Source/core/dom/ExecutionContext.cpp
diff --git a/Source/core/dom/ExecutionContext.cpp b/Source/core/dom/ExecutionContext.cpp
index 4ec9a88c8031b8d3d83268850358998f581dc5d5..d5c7b0fdf72d45613e709feeb7ae16bbb5312543 100644
--- a/Source/core/dom/ExecutionContext.cpp
+++ b/Source/core/dom/ExecutionContext.cpp
@@ -86,12 +86,14 @@ bool ExecutionContext::hasPendingActivity()
 
 void ExecutionContext::suspendActiveDOMObjects()
 {
+    ASSERT(!m_activeDOMObjectsAreSuspended);

[João Eiras, 2014/10/06 12:14:30]

This matches the asserts that already exist in SuspendableTimer, so it helps
finding problems sooner by putting them here.

     lifecycleNotifier().notifySuspendingActiveDOMObjects();
     m_activeDOMObjectsAreSuspended = true;
 }
 
 void ExecutionContext::resumeActiveDOMObjects()
 {
+    ASSERT(m_activeDOMObjectsAreSuspended);
     m_activeDOMObjectsAreSuspended = false;
     lifecycleNotifier().notifyResumingActiveDOMObjects();
 }