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

This reverts commit 48825b11ad25c98b9a4884d5cc0edd4e290c4409.

Reason for revert: nanobench

Original change's description:
> Redefine the meaning of sample counts in GPU backend.
> 
> Old: 0  -> nonMSAA
>      1+ -> MSAA
> 
> New:
>      0  -> error/unsupported
>      1  -> nonMSAA
>      2+ -> MSAA
> 
> We still allow 0 to mean nonMSAA in three sets of public APIs for backwards compatibility:
> 
> 1) SkSurface factories
> 2) GrBackendRenderTarget constructors
> 3) GrCaps::getSampleCnt()'s requestedCount parameter
> 
> However, we immediately clamp to 1 and treat 0 as invalid/non-renderable internally.
> 
> This also changes the behavior when using a large sample count. We now fail in that case rather than using the largest sample available sample count. GrCaps::getSampleCount() will return 0 in this case.
> 
> 
> Bug: skia:
> Change-Id: Ida22c6b22c1365e563c9046b611e88bf5eb3ff33
> Reviewed-on: https://skia-review.googlesource.com/101560
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

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

Change-Id: Ic257619a8a5ee9ac15419ecf10259e42daed7f82
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/102662
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/tests/ResourceCacheTest.cpp b/tests/ResourceCacheTest.cpp
index da2e278..34ed4f7 100644
--- a/tests/ResourceCacheTest.cpp
+++ b/tests/ResourceCacheTest.cpp
@@ -129,20 +129,21 @@
 
     GrResourceProvider* resourceProvider = context->contextPriv().resourceProvider();
 
-    sk_sp<GrRenderTarget> smallRT0 = create_RT_with_SB(resourceProvider, 4, 1, SkBudgeted::kYes);
+    sk_sp<GrRenderTarget> smallRT0 = create_RT_with_SB(resourceProvider, 4, 0, SkBudgeted::kYes);
     REPORTER_ASSERT(reporter, smallRT0);
 
     {
        // Two budgeted RTs with the same desc should share a stencil buffer.
-       sk_sp<GrRenderTarget> smallRT1 = create_RT_with_SB(resourceProvider, 4, 1, SkBudgeted::kYes);
-       REPORTER_ASSERT(reporter, smallRT1);
+        sk_sp<GrRenderTarget> smallRT1 = create_RT_with_SB(resourceProvider, 4, 0,
+                                                           SkBudgeted::kYes);
+        REPORTER_ASSERT(reporter, smallRT1);
 
-       REPORTER_ASSERT(reporter, get_SB(smallRT0.get()) == get_SB(smallRT1.get()));
+        REPORTER_ASSERT(reporter, get_SB(smallRT0.get()) == get_SB(smallRT1.get()));
     }
 
     {
         // An unbudgeted RT with the same desc should also share.
-        sk_sp<GrRenderTarget> smallRT2 = create_RT_with_SB(resourceProvider, 4, 1, SkBudgeted::kNo);
+        sk_sp<GrRenderTarget> smallRT2 = create_RT_with_SB(resourceProvider, 4, 0, SkBudgeted::kNo);
         REPORTER_ASSERT(reporter, smallRT2);
 
         REPORTER_ASSERT(reporter, get_SB(smallRT0.get()) == get_SB(smallRT2.get()));
@@ -150,14 +151,14 @@
 
     {
         // An RT with a much larger size should not share.
-        sk_sp<GrRenderTarget> bigRT = create_RT_with_SB(resourceProvider, 400, 1, SkBudgeted::kNo);
+        sk_sp<GrRenderTarget> bigRT = create_RT_with_SB(resourceProvider, 400, 0, SkBudgeted::kNo);
         REPORTER_ASSERT(reporter, bigRT);
 
         REPORTER_ASSERT(reporter, get_SB(smallRT0.get()) != get_SB(bigRT.get()));
     }
 
-    int smallSampleCount = context->caps()->getSampleCount(2, kRGBA_8888_GrPixelConfig);
-    if (smallSampleCount > 1) {
+    int smallSampleCount = context->caps()->getSampleCount(4, kRGBA_8888_GrPixelConfig);
+    if (smallSampleCount > 0) {
         // An RT with a different sample count should not share.
         sk_sp<GrRenderTarget> smallMSAART0 = create_RT_with_SB(resourceProvider, 4,
                                                                smallSampleCount, SkBudgeted::kNo);
@@ -182,10 +183,10 @@
             REPORTER_ASSERT(reporter, get_SB(smallMSAART0.get()) == get_SB(smallMSAART1.get()));
         }
 
-        // But one with a larger sample count should not. (Also check that the two requests didn't
-        // rounded up to the same actual sample count or else they could share.).
-        int bigSampleCount = context->caps()->getSampleCount(5, kRGBA_8888_GrPixelConfig);
-        if (bigSampleCount > 0 && bigSampleCount != smallSampleCount) {
+        // But not one with a larger sample count should not. (Also check that the request for 4
+        // samples didn't get rounded up to >= 8 or else they could share.).
+        int bigSampleCount = context->caps()->getSampleCount(8, kRGBA_8888_GrPixelConfig);
+        if (bigSampleCount != smallSampleCount) {
             sk_sp<GrRenderTarget> smallMSAART2 = create_RT_with_SB(resourceProvider, 4,
                                                                    bigSampleCount,
                                                                    SkBudgeted::kNo);
@@ -1706,7 +1707,7 @@
     {
         sk_sp<GrTexture> tex;
 
-        tex = make_normal_texture(resourceProvider, kRenderTarget_GrSurfaceFlag, kSize, kSize, 1);
+        tex = make_normal_texture(resourceProvider, kRenderTarget_GrSurfaceFlag, kSize, kSize, 0);
         size_t size = tex->gpuMemorySize();
         REPORTER_ASSERT(reporter, kSize*kSize*4 == size);
 
@@ -1721,7 +1722,7 @@
                             kSize*kSize*4*(sampleCount+1) == size);   // explicit resolve buffer
         }
 
-        tex = make_normal_texture(resourceProvider, kNone_GrSurfaceFlags, kSize, kSize, 1);
+        tex = make_normal_texture(resourceProvider, kNone_GrSurfaceFlags, kSize, kSize, 0);
         size = tex->gpuMemorySize();
         REPORTER_ASSERT(reporter, kSize*kSize*4 == size);
     }
@@ -1731,7 +1732,7 @@
     if (context->caps()->mipMapSupport()) {
         sk_sp<GrTextureProxy> proxy;
 
-        proxy = make_mipmap_proxy(proxyProvider, kRenderTarget_GrSurfaceFlag, kSize, kSize, 1);
+        proxy = make_mipmap_proxy(proxyProvider, kRenderTarget_GrSurfaceFlag, kSize, kSize, 0);
         size_t size = proxy->gpuMemorySize();
         REPORTER_ASSERT(reporter, kSize*kSize*4+(kSize*kSize*4)/3 == size);
 
@@ -1746,7 +1747,7 @@
                kSize*kSize*4*(sampleCount+1)+(kSize*kSize*4)/3 == size);  // explicit resolve buffer
         }
 
-        proxy = make_mipmap_proxy(proxyProvider, kNone_GrSurfaceFlags, kSize, kSize, 1);
+        proxy = make_mipmap_proxy(proxyProvider, kNone_GrSurfaceFlags, kSize, kSize, 0);
         size = proxy->gpuMemorySize();
         REPORTER_ASSERT(reporter, kSize*kSize*4+(kSize*kSize*4)/3 == size);
     }