replace setConfig+allocPixels with single call

tests/ShaderImageFilterTest.cpp

Index: tests/ShaderImageFilterTest.cpp
diff --git a/tests/ShaderImageFilterTest.cpp b/tests/ShaderImageFilterTest.cpp
index 96beed51a13e065ce711913336ccf72ab1418fc9..45fb5ca9a1d340ca41ef3e8300539789897346de 100644
--- a/tests/ShaderImageFilterTest.cpp
+++ b/tests/ShaderImageFilterTest.cpp
@@ -17,13 +17,11 @@ DEF_TEST(ShaderImageFilter, reporter) {
 
     SkBitmap filterResult, shaderResult;
 
-    filterResult.setConfig(SkBitmap::kARGB_8888_Config, w, h);
-    filterResult.allocPixels();
+    filterResult.allocN32Pixels(w, h);
     SkCanvas canvasFilter(filterResult);
     canvasFilter.clear(0x00000000);
 
-    shaderResult.setConfig(SkBitmap::kARGB_8888_Config, w, h);
-    shaderResult.allocPixels();
+    shaderResult.allocN32Pixels(w, h);
     SkCanvas canvasShader(shaderResult);
     canvasShader.clear(0x00000000);