Remove pixel config fallback - failing is a better option.

This produces surprising results in some cases. For example: Attempt to
make an F16 SkSurface on ANGLE. We can't render to F16, but this succeeds
and gives you back an N32 surface instead. Ran all tests and GMs in DM on
ANGLE (where this is most likely to be an issue). No problems.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2272423004

Review-Url: https://codereview.chromium.org/2272423004

1 files changed, 3 insertions, 6 deletions

diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index a6c8a1fc74..c91331f4b9 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -171,13 +171,10 @@ sk_sp<GrDrawContext> SkGpuDevice::MakeDrawContext(GrContext* context,
         at = kPremul_SkAlphaType;  // force this setting
     }
 
-    GrPixelConfig origConfig = SkImageInfo2GrPixelConfig(ct, at, cs, *context->caps());
-    if (!context->caps()->isConfigRenderable(origConfig, sampleCount > 0)) {
-        // Fall back from whatever ct was to default of kRGBA or kBGRA which is aliased as kN32
-        ct = kN32_SkColorType;
-    }
-
     GrPixelConfig config = SkImageInfo2GrPixelConfig(ct, at, cs, *context->caps());
+    if (!context->caps()->isConfigRenderable(config, sampleCount > 0)) {
+        return nullptr;
+    }
 
     return context->makeDrawContext(SkBackingFit::kExact,               // Why exact?
                                     origInfo.width(), origInfo.height(),