Add SkImageInfoValidConversion() and SkImageInfoIsValid

The idea is share these standards for the following:
SkImage::readPixels()
SkCanvas::readPixels()
SkCanvas::writePixels()
SkBitmap::readPixels()
SkPixmap::readPixels()

On the raster side, SkPixmap::readPixels() is the right
place to check, because all raster calls go through
there eventually.  Then at lower levels (ex: SkPixelInfo),
we can assert.

There's not really a unifying location for gpu calls,
so I've added this in multiple places.  I haven't really
dug into the gpu code to SkASSERT() on invalid cases
that we will have already caught.

Follow-up work:
Similar refactor for SkReadPixelRec::trim().
Code cleanup in SkPixelInfo::CopyPixels()

BUG=skia:6021

Change-Id: I91ecce10e46c1a6530f0af24a9eb8226dbecaaa2
Reviewed-on: https://skia-review.googlesource.com/6887
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Reed <reed@google.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/tests/SpecialImageTest.cpp b/tests/SpecialImageTest.cpp
index b0915f073f..33f394811a 100644
--- a/tests/SpecialImageTest.cpp
+++ b/tests/SpecialImageTest.cpp
@@ -88,7 +88,7 @@ static void test_image(const sk_sp<SkSpecialImage>& img, skiatest::Reporter* rep
     // Test that draw restricts itself to the subset
     SkImageFilter::OutputProperties outProps(img->getColorSpace());
     sk_sp<SkSpecialSurface> surf(img->makeSurface(outProps, SkISize::Make(kFullSize, kFullSize),
-                                                  kOpaque_SkAlphaType));
+                                                  kPremul_SkAlphaType));
 
     SkCanvas* canvas = surf->getCanvas();
 
@@ -96,7 +96,7 @@ static void test_image(const sk_sp<SkSpecialImage>& img, skiatest::Reporter* rep
     img->draw(canvas, SkIntToScalar(kPad), SkIntToScalar(kPad), nullptr);
 
     SkBitmap bm;
-    bm.allocN32Pixels(kFullSize, kFullSize, true);
+    bm.allocN32Pixels(kFullSize, kFullSize, false);
 
     bool result = canvas->readPixels(bm.info(), bm.getPixels(), bm.rowBytes(), 0, 0);
     SkASSERT_RELEASE(result);