Don't copy image buffer when calculating size.

tests/ImageTest.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <functional>
 #include <initializer_list>
 #include <vector>
@@ skipping 877 matching lines @@
         int                                                   fExpectedScaleFactor;
         bool                                                  fExpectation;
     } testCases[] = {
         { create_image,          {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
           kNone_SkFilterQuality, 1, true },
         { create_codec_image,    {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
           kNone_SkFilterQuality, 1, true },
         { create_data_image,     {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
           kNone_SkFilterQuality, 1, true },
         { create_picture_image,  {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
-          kNone_SkFilterQuality, 1, false },
+          kNone_SkFilterQuality, 1, true },

[cblume, 2016/09/16 08:10:45]

I am not yet familiar with the cacherator but as I stepped through this code,
everything seemed to make sense.

Do we really expect this to be failing?

[bsalomon, 2016/09/16 13:23:49]

We definitely don't want this one to succeed. It will sw-rasterize a picture
during decode time instead of gpu-rasterizing it during normal rasterization.

Perhaps we should add a query to SkImage_Base or the cacherator about whether
the image is encoded (if there isn't one already).

         { [context] { return create_gpu_image(context); },
           {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
           kNone_SkFilterQuality, 1, false },
         // Create a texture image in a another GrContext.
         { [testContext, otherContextInfo] {
             otherContextInfo.testContext()->makeCurrent();
             sk_sp<SkImage> otherContextImage = create_gpu_image(otherContextInfo.grContext());
             testContext->makeCurrent();
             return otherContextImage;
           }, {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
@@ skipping 114 matching lines @@
     SkBitmap bm1;
     bm1.allocPixels(SkImageInfo::MakeN32(256, 256, kUnpremul_SkAlphaType));
     bm0.readPixels(bm1.info(), bm1.getPixels(), bm1.rowBytes(), 0, 0);
 
     SkBitmap bm2;
     bm2.allocPixels(SkImageInfo::MakeN32(256, 256, kPremul_SkAlphaType));
     bm1.readPixels(bm2.info(), bm2.getPixels(), bm2.rowBytes(), 0, 0);
 
     REPORTER_ASSERT(reporter, equal(bm0, bm2));
 }