store SkAlphaType inside SkBitmap, on road to support unpremul

tests/ARGBImageEncoderTest.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /** Tests for ARGBImageEncoder. */
 
 #include "Test.h"
@@ skipping 30 matching lines @@
         0xff,0x00,0x00,0xff, 0xff,0x00,0x00,0xff, 0xff,0x00,0x00,0xff, // blue
     };
 
     SkAutoTDelete<SkImageEncoder> enc(CreateARGBImageEncoder());
     for (size_t configIndex = 0; configIndex < SK_ARRAY_COUNT(configs); ++configIndex) {
         // A bitmap that should generate the above bytes:
         SkBitmap bitmap;
         {
             bitmap.setConfig(configs[configIndex], kWidth, kHeight);
             REPORTER_ASSERT(reporter, bitmap.allocPixels());
-            bitmap.setIsOpaque(true);
+            bitmap.setAlphaType(kOpaque_SkAlphaType);
             bitmap.eraseColor(SK_ColorBLUE);
             // Change rows [0,1] from blue to [red,green].
             SkCanvas canvas(bitmap);
             SkPaint paint;
             paint.setColor(SK_ColorRED);
             canvas.drawIRect(SkIRect::MakeLTRB(0, 0, kWidth, 1), paint);
             paint.setColor(SK_ColorGREEN);
             canvas.drawIRect(SkIRect::MakeLTRB(0, 1, kWidth, 2), paint);
         }
 
         // Transform the bitmap.
         int bufferSize = bitmap.width() * bitmap.height() * 4;
         SkAutoMalloc pixelBufferManager(bufferSize);
         char *pixelBuffer = static_cast<char *>(pixelBufferManager.get());
         SkMemoryWStream out(pixelBuffer, bufferSize);
         REPORTER_ASSERT(reporter, enc->encodeStream(&out, bitmap, SkImageEncoder::kDefaultQuality));
 
         // Confirm we got the expected results.
         REPORTER_ASSERT(reporter, bufferSize == sizeof(comparisonBuffer));
         REPORTER_ASSERT(reporter, memcmp(pixelBuffer, comparisonBuffer, bufferSize) == 0);
     }
 }
 
 static TestRegistry gReg(BitmapTransformerTestClass::Factory);
 
 }