Return EphemeralRange from Editor::findRangeOfString.

third_party/WebKit/Source/core/editing/EphemeralRange.cpp

Index: third_party/WebKit/Source/core/editing/EphemeralRange.cpp
diff --git a/third_party/WebKit/Source/core/editing/EphemeralRange.cpp b/third_party/WebKit/Source/core/editing/EphemeralRange.cpp
index a578146ae9e2cb48ea7aad6e06331b761e872981..d4c05567f8d29c5ce6d24511aa4b28b8da56f2fd 100644
--- a/third_party/WebKit/Source/core/editing/EphemeralRange.cpp
+++ b/third_party/WebKit/Source/core/editing/EphemeralRange.cpp
@@ -144,6 +144,16 @@ PassRefPtrWillBeRawPtr<Range> createRange(const EphemeralRange& range)
     return Range::create(range.document(), range.startPosition(), range.endPosition());
 }
 
+PassRefPtrWillBeRawPtr<Range> createRange(const EphemeralRangeInComposedTree& range)

[yosin_UTC9, 2015/10/22 02:28:28]

Since DOM Range object can't represent a range crossing trees boundary.
Although, AFAKI, Range.cpp doesn't check this.
See Range::createAdjustedToTreeScope() how adjusting a range crossing 
tree boundary.

+{
+    if (range.isNull())
+        return nullptr;
+
+    return Range::create(range.document(),
+        toPositionInDOMTree(range.startPosition()),
+        toPositionInDOMTree(range.endPosition()));
+}
+
 template class CORE_TEMPLATE_EXPORT EphemeralRangeTemplate<EditingStrategy>;
 template class CORE_TEMPLATE_EXPORT EphemeralRangeTemplate<EditingInComposedTreeStrategy>;