store SkAlphaType inside SkBitmap, on road to support unpremul

BUG=
R=bsalomon@google.com, scroggo@google.com

Review URL: https://codereview.chromium.org/25275004

git-svn-id: http://skia.googlecode.com/svn/trunk@11877 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/DeferredCanvasTest.cpp b/tests/DeferredCanvasTest.cpp
index e8075bd..537a810 100644
--- a/tests/DeferredCanvasTest.cpp
+++ b/tests/DeferredCanvasTest.cpp
@@ -333,7 +333,7 @@
         paint.setStyle(SkPaint::kFill_Style);
         SkBitmap bmp;
         create(&bmp, SkBitmap::kARGB_8888_Config, 0xFFFFFFFF);
-        bmp.setIsOpaque(true);
+        bmp.setAlphaType(kOpaque_SkAlphaType);
         SkShader* shader = SkShader::CreateBitmapShader(bmp,
             SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
         paint.setShader(shader)->unref();
@@ -371,7 +371,7 @@
         paint.setStyle(SkPaint::kFill_Style);
         SkBitmap bmp;
         create(&bmp, SkBitmap::kARGB_8888_Config, 0xFFFFFFFF);
-        bmp.setIsOpaque(false);
+        bmp.setAlphaType(kPremul_SkAlphaType);
         SkShader* shader = SkShader::CreateBitmapShader(bmp,
             SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
         paint.setShader(shader)->unref();