add Method param to drawTextOnPath, supporting SVG spec

src/core/SkCanvas.cpp

Index: src/core/SkCanvas.cpp
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index c523ca07dd2c644088706507ac10d824feb60473..b059897bedb7fea9854b7496d5cd76a4cf1a25cc 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -2190,12 +2190,14 @@ void SkCanvas::onDrawPosTextH(const void* text, size_t byteLength, const SkScala
 }
 
 void SkCanvas::onDrawTextOnPath(const void* text, size_t byteLength, const SkPath& path,
-                                const SkMatrix* matrix, const SkPaint& paint) {
+                                const SkMatrix* matrix,
+                                SK_SUPPORT_LEGACY_DRAWTEXTONPATH_PARAM
+                                const SkPaint& paint) {
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type, NULL)
 
     while (iter.next()) {
         iter.fDevice->drawTextOnPath(iter, text, byteLength, path,
-                                     matrix, looper.paint());
+                                     matrix, SK_SUPPORT_LEGACY_DRAWTEXTONPATH_ARG looper.paint());
     }
 
     LOOPER_END
@@ -2239,9 +2241,14 @@ void SkCanvas::drawPosTextH(const void* text, size_t byteLength, const SkScalar
     this->onDrawPosTextH(text, byteLength, xpos, constY, paint);
 }
 void SkCanvas::drawTextOnPath(const void* text, size_t byteLength, const SkPath& path,
-                              const SkMatrix* matrix, const SkPaint& paint) {
+                              const SkMatrix* matrix, TextOnPathMethod method,
+                              const SkPaint& paint) {
+    if (0 == byteLength || path.isEmpty()) {
+        return;
+    }
     TRACE_EVENT0("disabled-by-default-skia", "SkCanvas::drawTextOnPath()");
-    this->onDrawTextOnPath(text, byteLength, path, matrix, paint);
+    this->onDrawTextOnPath(text, byteLength, path, matrix,
+                           SK_SUPPORT_LEGACY_DRAWTEXTONPATH_ARG paint);
 }
 void SkCanvas::drawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
                             const SkPaint& paint) {
@@ -2423,16 +2430,23 @@ void SkCanvas::drawArc(const SkRect& oval, SkScalar startAngle,
     }
 }
 
-void SkCanvas::drawTextOnPathHV(const void* text, size_t byteLength,
+#ifdef SK_SUPPORT_LEGACY_DRAWTEXTONPATH
+void SkCanvas::drawTextOnPathHV(const void* text, size_t length,
                                 const SkPath& path, SkScalar hOffset,
                                 SkScalar vOffset, const SkPaint& paint) {
     TRACE_EVENT0("disabled-by-default-skia", "SkCanvas::drawTextOnPathHV()");
     SkMatrix    matrix;
-
+    
     matrix.setTranslate(hOffset, vOffset);
-    this->drawTextOnPath(text, byteLength, path, &matrix, paint);
+    this->drawTextOnPath(text, length, path, &matrix, SkCanvas::kStretch_TextOnPathMethod, paint);
 }
 
+void SkCanvas::drawTextOnPath(const void* text, size_t length, const SkPath& path,
+                              const SkMatrix* matrix, const SkPaint& paint) {
+    this->drawTextOnPath(text, length, path, matrix, SkCanvas::kStretch_TextOnPathMethod, paint);
+}
+#endif
+
 ///////////////////////////////////////////////////////////////////////////////
 void SkCanvas::drawPicture(const SkPicture* picture) {
     TRACE_EVENT0("disabled-by-default-skia", "SkCanvas::drawPicture()");