Revert of Update Blink to use the tree scope info on WebFrame for scoping checks.

Source/core/page/FrameTree.cpp

Index: Source/core/page/FrameTree.cpp
diff --git a/Source/core/page/FrameTree.cpp b/Source/core/page/FrameTree.cpp
index 27677ce7cfd7db35886482923a4b133276633619..3c73ba1ff8529189d166609c663e38058ae67847 100644
--- a/Source/core/page/FrameTree.cpp
+++ b/Source/core/page/FrameTree.cpp
@@ -172,34 +172,62 @@
 
 Frame* FrameTree::scopedChild(unsigned index) const
 {
+    // TODO(dcheng, alexmos): Currently, all children of a RemoteFrame are
+    // visible, even through a shadow DOM scope.  Once RemoteFrames have a
+    // TreeScope, it should be used here.
+    TreeScope* scope = nullptr;
+    if (m_thisFrame->isLocalFrame()) {
+        scope = toLocalFrame(m_thisFrame)->document();
+        if (!scope)
+            return nullptr;
+    }
+
     unsigned scopedIndex = 0;
-    for (Frame* child = firstChild(); child; child = child->tree().nextSibling()) {
-        if (child->client()->inShadowTree())
+    for (Frame* result = firstChild(); result; result = result->tree().nextSibling()) {
+        // TODO(dcheng, alexmos): Currently, RemoteFrames are always visible,
+        // even through a shadow DOM scope. Once RemoteFrames have a TreeScope,
+        // the scoping check should apply to RemoteFrames too.
+        if (scope && result->isLocalFrame() && !toLocalFrame(result)->inScope(scope))
             continue;
         if (scopedIndex == index)
+            return result;
+        scopedIndex++;
+    }
+
+    return nullptr;
+}
+
+Frame* FrameTree::scopedChild(const AtomicString& name) const
+{
+    // TODO(dcheng, alexmos): Currently, all children of a RemoteFrame are
+    // visible, even through a shadow DOM scope.  Once RemoteFrames have a
+    // TreeScope, it should be used here.
+    TreeScope* scope = nullptr;
+    if (m_thisFrame->isLocalFrame()) {
+        scope = toLocalFrame(m_thisFrame)->document();
+        if (!scope)
+            return nullptr;
+    }
+
+    for (Frame* child = firstChild(); child; child = child->tree().nextSibling())
+        // TODO(dcheng, alexmos): Currently, RemoteFrames are always visible,
+        // even through a shadow DOM scope. Once RemoteFrames have a TreeScope,
+        // the scoping check should apply to RemoteFrames too.
+        if (child->tree().name() == name && (!scope || !child->isLocalFrame() || toLocalFrame(child)->inScope(scope)))
             return child;
-        scopedIndex++;
-    }
-
-    return nullptr;
-}
-
-Frame* FrameTree::scopedChild(const AtomicString& name) const
-{
-    for (Frame* child = firstChild(); child; child = child->tree().nextSibling()) {
-        if (child->client()->inShadowTree())
-            continue;
-        if (child->tree().name() == name)
-            return child;
-    }
     return nullptr;
 }
 
 inline unsigned FrameTree::scopedChildCount(TreeScope* scope) const
 {
+    // TODO(dcheng, alexmos): Once RemoteFrames have a TreeScope, this should
+    // return 0 if there is no scope.
+
     unsigned scopedCount = 0;
-    for (Frame* child = firstChild(); child; child = child->tree().nextSibling()) {
-        if (child->client()->inShadowTree())
+    for (Frame* result = firstChild(); result; result = result->tree().nextSibling()) {
+        // FIXME: Currently, RemoteFrames are always visible, even through a shadow DOM scope.
+        // Once RemoteFrames have a TreeScope, the scoping check should apply to RemoteFrames too.
+        if (scope && result->isLocalFrame() && !toLocalFrame(result)->inScope(scope))
             continue;
         scopedCount++;
     }