Return transform from transformationForTextBox instead of using out-param

Source/core/rendering/svg/SVGTextLayoutEngine.cpp

Index: Source/core/rendering/svg/SVGTextLayoutEngine.cpp
diff --git a/Source/core/rendering/svg/SVGTextLayoutEngine.cpp b/Source/core/rendering/svg/SVGTextLayoutEngine.cpp
index 9b9d6c7207ebd2ebc26795ab7ab895246849907d..236843120141752402d0fc0d2296f902940d1ada 100644
--- a/Source/core/rendering/svg/SVGTextLayoutEngine.cpp
+++ b/Source/core/rendering/svg/SVGTextLayoutEngine.cpp
@@ -292,10 +292,9 @@ void SVGTextLayoutEngine::finalizeTransformMatrices(Vector<SVGInlineTextBox*>& b
     if (!boxCount)
         return;
 
-    AffineTransform textBoxTransformation;
     for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
         SVGInlineTextBox* textBox = boxes.at(boxPosition);
-        m_chunkLayoutBuilder.transformationForTextBox(textBox, textBoxTransformation);
+        AffineTransform textBoxTransformation = m_chunkLayoutBuilder.transformationForTextBox(textBox);

[pdr., 2014/07/08 19:00:44]

I think this will create an unnecessary copy. Should we use const
AffineTransform& textBoxTransformation here?

[fs, 2014/07/09 08:53:53]

This should be fine - at least the compiler I used applied RVO here. (There's a
redundant copy emitted for the identity-case transformationForTextBox() though -
fixable, but adds unnecessary contortions IMHO.)

         if (textBoxTransformation.isIdentity())
             continue;