Refactor the current text position update in SVGTextLayoutEngine

third_party/WebKit/Source/core/layout/svg/SVGTextLayoutEngine.h

Index: third_party/WebKit/Source/core/layout/svg/SVGTextLayoutEngine.h
diff --git a/third_party/WebKit/Source/core/layout/svg/SVGTextLayoutEngine.h b/third_party/WebKit/Source/core/layout/svg/SVGTextLayoutEngine.h
index fc510dfec94e157245de711946e81e9649ba7a5b..a65073897de0f77567fca1ac9fb5983051ff192a 100644
--- a/third_party/WebKit/Source/core/layout/svg/SVGTextLayoutEngine.h
+++ b/third_party/WebKit/Source/core/layout/svg/SVGTextLayoutEngine.h
@@ -58,9 +58,9 @@ public:
     void finishLayout();
 
 private:
-    void updateCharacterPositionIfNeeded(float& x, float& y);
-    void updateCurrentTextPosition(float x, float y, float glyphAdvance);
-    void updateRelativePositionAdjustmentsIfNeeded(float dx, float dy);
+    bool setCurrentTextPositionIfNeeded(const SVGCharacterData&);

[pdr., 2016/04/14 01:05:52]

Optional bikeshed: -isNeeded seems to have fallen out of favor lately. I have
mixed feelings about using -isNeeded for expensive operations since it makes
performance issues clear at callsites, but in this case we could remove it
without harm.

[fs, 2016/04/14 08:56:42]

Dropped suffix.

+    void advanceCurrentTextPosition(float glyphAdvance);
+    bool applyRelativePositionAdjustmentsIfNeeded(const SVGCharacterData&);
 
     void computeCurrentFragmentMetrics(SVGInlineTextBox*);
     void recordTextFragment(SVGInlineTextBox*);
@@ -85,10 +85,7 @@ private:
     unsigned m_logicalCharacterOffset;
     unsigned m_logicalMetricsListOffset;
     SVGInlineTextMetricsIterator m_visualMetricsIterator;
-    float m_x;
-    float m_y;
-    float m_dx;
-    float m_dy;
+    FloatPoint m_ctp;

[pdr., 2016/04/14 01:05:52]

+1 to merging these into a FloatPoint, but ctp isn't a very common acronym. WDYT
of "m_textPosition"?

[fs, 2016/04/14 08:56:42]

For me it's a very common acronym =D [1]. I guess I don't count though, so
changed.

[1] https://www.w3.org/TR/SVG11/text.html#CurrentTextPosition

     bool m_isVerticalText;
     bool m_inPathLayout;
     bool m_textLengthSpacingInEffect;
@@ -97,6 +94,7 @@ private:
     OwnPtr<PathPositionMapper> m_textPath;
     float m_textPathStartOffset;
     float m_textPathCurrentOffset;
+    float m_textPathDisplacement;
     float m_textPathSpacing;
     float m_textPathScaling;
 };