Consistently fail readPixels when rowbytes not a multiple of bpp

Previously this would report success but may have rounded the
rowbytes down to a multiple of bpp prior to writing the dst.
On GPU it could trigger an assert in a debug build.

Bug: chromium:1163061
Change-Id: I19709f4cdb71139732998a4dd2e14476099f0ba8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/363782
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Mike Reed <reed@google.com>
diff --git a/src/utils/SkPatchUtils.cpp b/src/utils/SkPatchUtils.cpp
index 9ca2633..009c3c6 100644
--- a/src/utils/SkPatchUtils.cpp
+++ b/src/utils/SkPatchUtils.cpp
@@ -223,7 +223,7 @@
                                             kUnpremul_SkAlphaType, SkColorSpace::MakeSRGB());
     SkImageInfo dstInfo = SkImageInfo::Make(count, 1, kRGBA_F32_SkColorType,
                                             kPremul_SkAlphaType, sk_ref_sp(dstCS));
-    SkConvertPixels(dstInfo, dst, 0, srcInfo, src, 0);
+    SkAssertResult(SkConvertPixels(dstInfo, dst, 0, srcInfo, src, 0));
 }
 
 static void float_to_skcolor(SkColor* dst, const SkPMColor4f* src, int count, SkColorSpace* srcCS) {
@@ -231,7 +231,7 @@
                                             kPremul_SkAlphaType, sk_ref_sp(srcCS));
     SkImageInfo dstInfo = SkImageInfo::Make(count, 1, kBGRA_8888_SkColorType,
                                             kUnpremul_SkAlphaType, SkColorSpace::MakeSRGB());
-    SkConvertPixels(dstInfo, dst, 0, srcInfo, src, 0);
+    SkAssertResult(SkConvertPixels(dstInfo, dst, 0, srcInfo, src, 0));
 }
 
 sk_sp<SkVertices> SkPatchUtils::MakeVertices(const SkPoint cubics[12], const SkColor srcColors[4],