Revert "Revert "Revert "Allow FPs to elevate default precision for the entire fragment program"""

This reverts commit ec53c636b781830cb6146bb32106d4ee44651fcc.

Reason for revert: Mali GMs look bad.

Original change's description:
> Revert "Revert "Allow FPs to elevate default precision for the entire fragment program""
> 
> This reverts commit 903c3f70400462e191ccbca63393b2df3fe2dd11.
> 
> Reason for revert: Vulkan issue fixed in compiler.
> 
> Original change's description:
> > Revert "Allow FPs to elevate default precision for the entire fragment program"
> > 
> > This reverts commit 92d7ccafdf896cf19764e025873d13315a76842d.
> > 
> > Reason for revert: Vulkan errors.
> > 
> > Original change's description:
> > > Allow FPs to elevate default precision for the entire fragment program
> > > 
> > > Currently, GrConfigConversionEffect is able to round-trip on many mobile
> > > GPUs because it uses highp for all intermediate variables (including the
> > > texture fetch result). Separating the texture sample into a different
> > > processor breaks that.
> > > 
> > > This is a blunt instrument, not to be used lightly.
> > > 
> > > Bug: skia:
> > > Change-Id: I2ab365e3da79628069e2eb727c43c2bf45bfd789
> > > Reviewed-on: https://skia-review.googlesource.com/10162
> > > Reviewed-by: Brian Salomon <bsalomon@google.com>
> > > Commit-Queue: Brian Osman <brianosman@google.com>
> > > 
> > 
> > TBR=bsalomon@google.com,robertphillips@google.com,brianosman@google.com,ethannicholas@google.com,reviews@skia.org
> > NOPRESUBMIT=true
> > NOTREECHECKS=true
> > NOTRY=true
> > 
> > Change-Id: Iee5bb409f86a9cabecc76bd1273a5b3cef6af179
> > Reviewed-on: https://skia-review.googlesource.com/10967
> > Reviewed-by: Brian Osman <brianosman@google.com>
> > Commit-Queue: Brian Osman <brianosman@google.com>
> > 
> 
> TBR=bsalomon@google.com,robertphillips@google.com,reviews@skia.org,brianosman@google.com,ethannicholas@google.com
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> 
> Change-Id: I733a0ecc40b58d8727f0259b5498c8e6610cedce
> Reviewed-on: https://skia-review.googlesource.com/11010
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>
> 

TBR=bsalomon@google.com,robertphillips@google.com,reviews@skia.org,brianosman@google.com,ethannicholas@google.com
# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: Ic3274a0a8b776e811354c3441391ffdc80678292
Reviewed-on: https://skia-review.googlesource.com/11061
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/src/gpu/GrShaderCaps.cpp b/src/gpu/GrShaderCaps.cpp
index 636b955ab7..e3e6b07361 100644
--- a/src/gpu/GrShaderCaps.cpp
+++ b/src/gpu/GrShaderCaps.cpp
@@ -32,10 +32,8 @@ static const char* precision_to_string(GrSLPrecision p) {
         return "medium";
     case kHigh_GrSLPrecision:
         return "high";
-    default:
-        SkFAIL("Unexpected precision type.");
-        return "";
     }
+    return "";
 }
 
 GrShaderCaps::GrShaderCaps(const GrContextOptions& options) {
@@ -203,7 +201,7 @@ void GrShaderCaps::initSamplerPrecisionTable() {
         }
 
         uint8_t* table = fSamplerPrecisions[visibility];
-        table[kUnknown_GrPixelConfig]        = lowp;
+        table[kUnknown_GrPixelConfig]        = kDefault_GrSLPrecision;
         table[kAlpha_8_GrPixelConfig]        = lowp;
         table[kGray_8_GrPixelConfig]         = lowp;
         table[kRGB_565_GrPixelConfig]        = lowp;