hide SkBitmap::setConfig

patch from issue 325733002

TBR=scroggo

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/322963002
diff --git a/bench/DisplacementBench.cpp b/bench/DisplacementBench.cpp
index 08da9b1..904f47d 100644
--- a/bench/DisplacementBench.cpp
+++ b/bench/DisplacementBench.cpp
@@ -33,10 +33,8 @@
     void makeBitmap() {
         const int w = this->isSmall() ? FILTER_WIDTH_SMALL : FILTER_WIDTH_LARGE;
         const int h = this->isSmall() ? FILTER_HEIGHT_LARGE : FILTER_HEIGHT_LARGE;
-        fBitmap.setConfig(SkBitmap::kARGB_8888_Config, w, h);
-        fBitmap.allocPixels();
-        SkBitmapDevice device(fBitmap);
-        SkCanvas canvas(&device);
+        fBitmap.allocN32Pixels(w, h);
+        SkCanvas canvas(fBitmap);
         canvas.clear(0x00000000);
         SkPaint paint;
         paint.setAntiAlias(true);
@@ -49,10 +47,8 @@
     void makeCheckerboard() {
         const int w = this->isSmall() ? FILTER_WIDTH_SMALL : FILTER_WIDTH_LARGE;
         const int h = this->isSmall() ? FILTER_HEIGHT_LARGE : FILTER_HEIGHT_LARGE;
-        fCheckerboard.setConfig(SkBitmap::kARGB_8888_Config, w, h);
-        fCheckerboard.allocPixels();
-        SkBitmapDevice device(fCheckerboard);
-        SkCanvas canvas(&device);
+        fCheckerboard.allocN32Pixels(w, h);
+        SkCanvas canvas(fCheckerboard);
         canvas.clear(0x00000000);
         SkPaint darkPaint;
         darkPaint.setColor(0xFF804020);