Add UseCounter for multiple createShadowRoot() for deprecation

Source/core/dom/shadow/ElementShadow.cpp

Index: Source/core/dom/shadow/ElementShadow.cpp
diff --git a/Source/core/dom/shadow/ElementShadow.cpp b/Source/core/dom/shadow/ElementShadow.cpp
index ad449159c82d820e2b629b0609037e6acb4b7aa4..a34db2133d1929af90d15a7ac22627b9d1062906 100644
--- a/Source/core/dom/shadow/ElementShadow.cpp
+++ b/Source/core/dom/shadow/ElementShadow.cpp
@@ -31,6 +31,7 @@
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/shadow/DistributedNodes.h"
+#include "core/frame/UseCounter.h"
 #include "core/html/HTMLContentElement.h"
 #include "core/html/HTMLShadowElement.h"
 #include "core/inspector/InspectorInstrumentation.h"
@@ -149,6 +150,8 @@ ShadowRoot& ElementShadow::addShadowRoot(Element& shadowHost, ShadowRoot::Shadow
 
     if (type == ShadowRoot::OpenShadowRoot && (!youngestShadowRoot() || youngestShadowRoot()->type() == ShadowRoot::UserAgentShadowRoot))
         shadowHost.willAddFirstOpenShadowRoot();
+    else

[hayato, 2015/05/20 02:10:04]

Will this count UserAgent ShadowRoot also?

[kochi, 2015/05/20 02:26:25]

Good catch. fixed.

+        UseCounter::count(shadowHost.document(), UseCounter::DeprecatedMultipleElementCreateShadowRoot);
 
     for (ShadowRoot* root = youngestShadowRoot(); root; root = root->olderShadowRoot())
         root->lazyReattachIfAttached();