make drawText calls non-virtual, to ease SkFont and TextBlob

include/core/SkCanvas.h

Index: include/core/SkCanvas.h
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index 0a819694684540a99a1091fd0a030efc7f2292de..479503eaa9d293e768366aecf6887619944e64e0 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -26,6 +26,13 @@
 //#define SK_SUPPORT_LEGACY_GETTOTALCLIP
 //#define SK_SUPPORT_LEGACY_GETTOPDEVICE
 
+//#define SK_SUPPORT_LEGACY_DRAWTEXT_VIRTUAL
+#ifdef SK_SUPPORT_LEGACY_DRAWTEXT_VIRTUAL
+    #define SK_LEGACY_DRAWTEXT_VIRTUAL  virtual
+#else
+    #define SK_LEGACY_DRAWTEXT_VIRTUAL
+#endif
+
 class SkBounder;
 class SkBaseDevice;
 class SkDraw;
@@ -868,7 +875,7 @@ public:
         @param y        The y-coordinate of the origin of the text being drawn
         @param paint    The paint used for the text (e.g. color, size, style)
     */
-    virtual void drawText(const void* text, size_t byteLength, SkScalar x,
+    SK_LEGACY_DRAWTEXT_VIRTUAL void drawText(const void* text, size_t byteLength, SkScalar x,
                           SkScalar y, const SkPaint& paint);
 
     /** Draw the text, with each character/glyph origin specified by the pos[]
@@ -878,7 +885,7 @@ public:
         @param pos      Array of positions, used to position each character
         @param paint    The paint used for the text (e.g. color, size, style)
         */
-    virtual void drawPosText(const void* text, size_t byteLength,
+    SK_LEGACY_DRAWTEXT_VIRTUAL void drawPosText(const void* text, size_t byteLength,
                              const SkPoint pos[], const SkPaint& paint);
 
     /** Draw the text, with each character/glyph origin specified by the x
@@ -890,7 +897,7 @@ public:
         @param constY   The shared Y coordinate for all of the positions
         @param paint    The paint used for the text (e.g. color, size, style)
         */
-    virtual void drawPosTextH(const void* text, size_t byteLength,
+    SK_LEGACY_DRAWTEXT_VIRTUAL void drawPosTextH(const void* text, size_t byteLength,
                               const SkScalar xpos[], SkScalar constY,
                               const SkPaint& paint);
 
@@ -920,7 +927,7 @@ public:
                             mapped onto the path
         @param paint        The paint used for the text
         */
-    virtual void drawTextOnPath(const void* text, size_t byteLength,
+    SK_LEGACY_DRAWTEXT_VIRTUAL void drawTextOnPath(const void* text, size_t byteLength,
                                 const SkPath& path, const SkMatrix* matrix,
                                 const SkPaint& paint);
 
@@ -1186,6 +1193,22 @@ protected:
 
     virtual void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&);
 
+#ifndef SK_SUPPORT_LEGACY_DRAWTEXT_VIRTUAL
+    virtual void onDrawText(const void* text, size_t byteLength, SkScalar x,
+                            SkScalar y, const SkPaint& paint);
+    
+    virtual void onDrawPosText(const void* text, size_t byteLength,
+                               const SkPoint pos[], const SkPaint& paint);
+    
+    virtual void onDrawPosTextH(const void* text, size_t byteLength,
+                                const SkScalar xpos[], SkScalar constY,
+                                const SkPaint& paint);
+    
+    virtual void onDrawTextOnPath(const void* text, size_t byteLength,
+                                  const SkPath& path, const SkMatrix* matrix,
+                                  const SkPaint& paint);
+#endif
+
     enum ClipEdgeStyle {
         kHard_ClipEdgeStyle,
         kSoft_ClipEdgeStyle