update bitmapshader to avoid potential rendering error for kA8_Config

gm/bitmapshader.cpp

Index: gm/bitmapshader.cpp
diff --git a/gm/bitmapshader.cpp b/gm/bitmapshader.cpp
index fb563070d1d19abf01677dac68609eccfcdf2b82..99262bbf706d54bc21dcb5ae0205537da4f7bedd 100644
--- a/gm/bitmapshader.cpp
+++ b/gm/bitmapshader.cpp
@@ -35,7 +35,8 @@ static void draw_mask(SkBitmap* bm) {
     canvas.drawCircle(10, 10, 10, circlePaint);
 }
 
-static void adopt_shader(SkPaint* paint, SkShader* shader) {
+static void adopt_shader(SkPaint* paint, SkShader* shader, SkMatrix s) {
+    shader->setLocalMatrix(s);
     paint->setShader(shader);
     SkSafeUnref(shader);
 }
@@ -55,33 +56,53 @@ protected:
     }
 
     virtual SkISize onISize() {
-        return SkISize::Make(75, 100);
+        return SkISize::Make(150, 100);
     }
 
     virtual void onDraw(SkCanvas* canvas) {
         SkPaint paint;
 
-        adopt_shader(&paint, SkShader::CreateBitmapShader(fBitmap, SkShader::kClamp_TileMode,
-                                                          SkShader::kClamp_TileMode));
+        for (int i = 0; i < 2; i++) {
+            SkMatrix s;
+            s.reset();
+            if (1 == i) {
+                s.setScale(1.5, 1.5);
+                s.postTranslate(2, 2);
+            }
 
-        // draw the shader with a bitmap mask
-        canvas->drawBitmap(fMask, 0, 0, &paint);
-        canvas->drawBitmap(fMask, 30, 0, &paint);
+            canvas->save();
+            adopt_shader(&paint, SkShader::CreateBitmapShader(fBitmap, SkShader::kClamp_TileMode,
+                                                              SkShader::kClamp_TileMode), s);
 
-        canvas->translate(0, 25);
+            // draw the shader with a bitmap mask
+            canvas->drawBitmap(fMask, 0, 0, &paint);
+            canvas->drawBitmap(fMask, 30, 0, &paint);
 
-        canvas->drawCircle(10, 10, 10, paint);
-        canvas->drawCircle(40, 10, 10, paint); // no blue circle expected
+            canvas->translate(0, 25);
 
-        canvas->translate(0, 25);
+            canvas->drawCircle(10, 10, 10, paint);
+            canvas->drawCircle(40, 10, 10, paint); // no blue circle expected
 
-        adopt_shader(&paint, SkShader::CreateBitmapShader(fMask, SkShader::kRepeat_TileMode,
-                                                          SkShader::kRepeat_TileMode));
-        paint.setColor(SK_ColorRED);
+            canvas->translate(0, 25);
 
-        // draw the mask using the shader and a color
-        canvas->drawRect(SkRect::MakeXYWH(0, 0, 20, 20), paint);
-        canvas->drawRect(SkRect::MakeXYWH(30, 0, 20, 20), paint);
+            // clear the shader, colorized by a solid color with a bitmap mask
+            paint.setShader(NULL);
+            paint.setColor(SK_ColorGREEN);
+            canvas->drawBitmap(fMask, 0, 0, &paint);
+            canvas->drawBitmap(fMask, 30, 0, &paint);
+
+            canvas->translate(0, 25);
+
+            adopt_shader(&paint, SkShader::CreateBitmapShader(fMask, SkShader::kRepeat_TileMode,
+                                                              SkShader::kRepeat_TileMode), s);
+            paint.setColor(SK_ColorRED);
+
+            // draw the mask using the shader and a color
+            canvas->drawRect(SkRect::MakeXYWH(0, 0, 20, 20), paint);
+            canvas->drawRect(SkRect::MakeXYWH(30, 0, 20, 20), paint);
+            canvas->restore();
+            canvas->translate(60, 0);
+        }
     }
 
 private: