Revert "Revert "Revert "Revert "Revert "Redefine the meaning of sample counts in GPU backend."""""

This reverts commit 5bb82cbecd740d21b92e8d2944280ab6eb6af7a6.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Revert "Revert "Revert "Revert "Redefine the meaning of sample counts in GPU backend.""""
> 
> This reverts commit 18c52a7b52211de5d0dcd86dc048adef758c6c75.
> 
> Also relands "More sample count cleanup:" and "Add new GrContext queries for imagability, surfacability, and max sample count of color types"
> 
> 
> Bug: skia:
> Change-Id: I4028105a3a1f16ce3944e134619eb6245af6b947
> Reviewed-on: https://skia-review.googlesource.com/102940
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

TBR=egdaniel@google.com,bsalomon@google.com

Change-Id: Idee23be2f1719f0bdc9305043e95a2d589bee8d1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/103220
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

3 files changed, 21 insertions, 26 deletions

diff --git a/src/gpu/mtl/GrMtlCaps.h b/src/gpu/mtl/GrMtlCaps.h
index 935cb07822..6204eaac5a 100644
--- a/src/gpu/mtl/GrMtlCaps.h
+++ b/src/gpu/mtl/GrMtlCaps.h
@@ -24,12 +24,20 @@ public:
     GrMtlCaps(const GrContextOptions& contextOptions, id<MTLDevice> device,
               MTLFeatureSet featureSet);
 
+    int getSampleCount(int requestedCount, GrPixelConfig config) const override;
+
     bool isConfigTexturable(GrPixelConfig config) const override {
         return SkToBool(fConfigTable[config].fFlags & ConfigInfo::kTextureable_Flag);
     }
 
-    int getRenderTargetSampleCount(int requestedCount, GrPixelConfig) const override;
-    int maxRenderTargetSampleCount(GrPixelConfig) const override;
+    bool isConfigRenderable(GrPixelConfig config, bool withMSAA) const override {
+        if (withMSAA) {
+            return SkToBool(fConfigTable[config].fFlags & ConfigInfo::kRenderable_Flag) &&
+                   SkToBool(fConfigTable[config].fFlags & ConfigInfo::kMSAA_Flag);
+        } else {
+            return SkToBool(fConfigTable[config].fFlags & ConfigInfo::kRenderable_Flag);
+        }
+    }
 
     bool isConfigCopyable(GrPixelConfig config) const override {
         return true;
diff --git a/src/gpu/mtl/GrMtlCaps.mm b/src/gpu/mtl/GrMtlCaps.mm
index 0bb7530fe2..2bce74a261 100644
--- a/src/gpu/mtl/GrMtlCaps.mm
+++ b/src/gpu/mtl/GrMtlCaps.mm
@@ -121,7 +121,7 @@ void GrMtlCaps::initGrCaps(const id<MTLDevice> device) {
     fMaxTextureSize = fMaxRenderTargetSize;
 
     // Init sample counts. All devices support 1 (i.e. 0 in skia).
-    fSampleCounts.push(1);
+    fSampleCounts.push(0);
     for (auto sampleCnt : {2, 4, 8}) {
         if ([device supportsTextureSampleCount:sampleCnt]) {
             fSampleCounts.push(sampleCnt);
@@ -164,29 +164,19 @@ void GrMtlCaps::initGrCaps(const id<MTLDevice> device) {
     fCrossContextTextureSupport = false;
 }
 
-
-int GrMtlCaps::maxRenderTargetSampleCount(GrPixelConfig config) const {
-    if (fConfigTable[config].fFlags & ConfigInfo::kMSAA_Flag) {
-        return fSampleCounts[fSampleCounts.count() - 1];
-    } else if (fConfigTable[config].fFlags & ConfigInfo::kRenderable_Flag) {
-        return 1;
+int GrMtlCaps::getSampleCount(int requestedCount, GrPixelConfig config) const {
+    int count = fSampleCounts.count();
+    SkASSERT(count > 0); // We always add 0 as a valid sample count
+    if (!this->isConfigRenderable(config, true)) {
+        return 0;
     }
-    return 0;
-}
 
-int GrMtlCaps::getRenderTargetSampleCount(int requestedCount, GrPixelConfig config) const {
-    requestedCount = SkTMax(requestedCount, 1);
-    if (fConfigTable[config].fFlags & ConfigInfo::kMSAA_Flag) {
-        int count = fSampleCounts.count();
-        for (int i = 0; i < count; ++i) {
-            if (fSampleCounts[i] >= requestedCount) {
-                return fSampleCounts[i];
-            }
+    for (int i = 0; i < count; ++i) {
+        if (fSampleCounts[i] >= requestedCount) {
+            return fSampleCounts[i];
         }
-    } else if (fConfigTable[config].fFlags & ConfigInfo::kRenderable_Flag) {
-        return 1 == requestedCount ? 1 : 0;
     }
-    return 0;
+    return fSampleCounts[count-1];
 }
 
 void GrMtlCaps::initShaderCaps() {
diff --git a/src/gpu/mtl/GrMtlRenderTarget.h b/src/gpu/mtl/GrMtlRenderTarget.h
index 83e7d3c240..4dac306e7e 100644
--- a/src/gpu/mtl/GrMtlRenderTarget.h
+++ b/src/gpu/mtl/GrMtlRenderTarget.h
@@ -63,11 +63,8 @@ protected:
 
     // This accounts for the texture's memory and any MSAA renderbuffer's memory.
     size_t onGpuMemorySize() const override {
-        int numColorSamples = this->numColorSamples();
         // The plus 1 is to account for the resolve texture or if not using msaa the RT itself
-        if (numColorSamples > 1) {
-            ++numColorSamples;
-        }
+        int numColorSamples = this->numColorSamples() + 1;
         return GrSurface::ComputeSize(this->config(), this->width(), this->height(),
                                       numColorSamples, GrMipMapped::kNo);
     }