Oilpan: Introduce TempRangeScope to avoid needless Range attaches on Document.

Source/core/dom/Range.cpp

Index: Source/core/dom/Range.cpp
diff --git a/Source/core/dom/Range.cpp b/Source/core/dom/Range.cpp
index 241c62f3c20656a65b4b824ff15af8159d15036e..9e354ce4a3076bd58f48fecfcc6aa36d55eaa521 100644
--- a/Source/core/dom/Range.cpp
+++ b/Source/core/dom/Range.cpp
@@ -57,6 +57,10 @@ namespace WebCore {
 
 DEFINE_DEBUG_ONLY_GLOBAL(WTF::RefCountedLeakCounter, rangeCounter, ("Range"));
 
+#if ENABLE(OILPAN)
+unsigned TemporaryRangeScope::s_nesting = 0;
+#endif
+
 inline Range::Range(Document& ownerDocument)
     : m_ownerDocument(&ownerDocument)
     , m_start(m_ownerDocument)
@@ -65,9 +69,9 @@ inline Range::Range(Document& ownerDocument)
 #ifndef NDEBUG
     rangeCounter.increment();
 #endif
-
     ScriptWrappable::init(this);
-    m_ownerDocument->attachRange(this);
+    if (!TemporaryRangeScope::active())

[haraken, 2014/06/24 12:24:22]

You can move this check into Document::attachRange, since we're verifying
!TemporaryRangeScope::active() in Document's methods.

+        m_ownerDocument->attachRange(this);
 }
 
 PassRefPtrWillBeRawPtr<Range> Range::create(Document& ownerDocument)
@@ -83,9 +87,9 @@ inline Range::Range(Document& ownerDocument, Node* startContainer, int startOffs
 #ifndef NDEBUG
     rangeCounter.increment();
 #endif
-
     ScriptWrappable::init(this);
-    m_ownerDocument->attachRange(this);
+    if (!TemporaryRangeScope::active())

[haraken, 2014/06/24 12:24:22]

Ditto.

+        m_ownerDocument->attachRange(this);
 
     // Simply setting the containers and offsets directly would not do any of the checking
     // that setStart and setEnd do, so we call those functions.