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/ShaderOpacityTest.cpp b/tests/ShaderOpacityTest.cpp
index 0af25d1..c3dc888 100644
--- a/tests/ShaderOpacityTest.cpp
+++ b/tests/ShaderOpacityTest.cpp
@@ -32,7 +32,7 @@
     shader->unref();
 
     // test 3: explicitly opaque
-    bmp.setIsOpaque(true);
+    bmp.setAlphaType(kOpaque_SkAlphaType);
     shader = SkShader::CreateBitmapShader(bmp,
         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
     REPORTER_ASSERT(reporter, shader);
@@ -40,7 +40,7 @@
     shader->unref();
 
     // test 4: explicitly not opaque
-    bmp.setIsOpaque(false);
+    bmp.setAlphaType(kPremul_SkAlphaType);
     shader = SkShader::CreateBitmapShader(bmp,
         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
     REPORTER_ASSERT(reporter, shader);