Move RenderTextInfo and WordMeasurement into their own headers.

Source/core/rendering/RenderBlockLineLayout.cpp

Index: Source/core/rendering/RenderBlockLineLayout.cpp
diff --git a/Source/core/rendering/RenderBlockLineLayout.cpp b/Source/core/rendering/RenderBlockLineLayout.cpp
index 696ab86c8a235418551b80acf30aa4b1556a46d3..bf4ef4a89f934be907b19d5d2fdbbf6cfc5b95c5 100644
--- a/Source/core/rendering/RenderBlockLineLayout.cpp
+++ b/Source/core/rendering/RenderBlockLineLayout.cpp
@@ -35,6 +35,8 @@
 #include "core/rendering/line/BreakingContextInlineHeaders.h"
 #include "core/rendering/line/LineLayoutState.h"
 #include "core/rendering/line/LineWidth.h"
+#include "core/rendering/line/RenderTextInfo.h"
+#include "core/rendering/line/WordMeasurement.h"
 #include "core/rendering/svg/SVGRootInlineBox.h"
 #include "platform/fonts/Character.h"
 #include "platform/text/BidiResolver.h"
@@ -918,16 +920,6 @@ void RenderBlockFlow::layoutRunsAndFloats(LineLayoutState& layoutState)
     repaintDirtyFloats(layoutState.floats());
 }
 
-RenderTextInfo::RenderTextInfo()
-    : m_text(0)
-    , m_font(0)
-{
-}
-
-RenderTextInfo::~RenderTextInfo()
-{
-}
-
 // Before restarting the layout loop with a new logicalHeight, remove all floats that were added and reset the resolver.
 inline const InlineIterator& RenderBlockFlow::restartLayoutRunsAndFloatsInRange(LayoutUnit oldLogicalHeight, LayoutUnit newLogicalHeight,  FloatingObject* lastFloatFromPreviousLine, InlineBidiResolver& resolver,  const InlineIterator& oldEnd)
 {