fix the rendering error for drawPosText_asPaths

src/core/SkPaint.cpp

Index: src/core/SkPaint.cpp
diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index 88e5b432eb8d714bb4ae52d716844d22f01e537a..bd3961a5ae6039c282997031769a44d76e3c82c7 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -996,8 +996,25 @@ SkScalar SkPaint::setupForAsPaths() {
     this->setHinting(SkPaint::kNo_Hinting);
 
     SkScalar textSize = fTextSize;
-    this->setTextSize(kCanonicalTextSizeForPaths);
-    return textSize / kCanonicalTextSizeForPaths;
+    SkScalar scale = SK_Scalar1;
+
+    // path effect will affects the generation of path for text, don't change
+    // SkPaint if it exists. If no path effect, text drawing is based on 
+    // canonical text, so textSize and strokeWidth need to be reset. However,
+    // hairline stroked text is treated as filled to generate its path.
+    if (NULL == this->getPathEffect()) {
+        this->setTextSize(kCanonicalTextSizeForPaths);
+        scale = textSize / kCanonicalTextSizeForPaths;
+
+        if (this->getStrokeWidth() > 0 &&
+            SkPaint::kFill_Style != this->getStyle()) {
+            this->setStrokeWidth(SkScalarDiv(this->getStrokeWidth(), scale));
+        } else {
+            this->setStyle(SkPaint::kFill_Style);
+        }
+    }
+
+    return scale;
 }
 
 class SkCanonicalizePaint {