Revert of Alter gpu veto (patchset #1 id:1 of https://codereview.chromium.org/875913002/)

Reason for revert:
Failing tests

Original issue's description:
> Alter gpu veto
>
> This CL unifies the treatment of the dashed and concave paths.
>
> Before:
> TP 28 FP 15 TN 8 FN 3 IND 3
>
> After:
> TP 28 FP 18 TN 7 FN 2 IND 2
>
> One of the TrueNegatives that became a FalsePositive was the motivation use case (the Chromium busy spinner).
>
> Committed: https://skia.googlesource.com/skia/+/87a6a8e18c7d5bbc94f478b44c53dc0e0549f927

TBR=egdaniel@google.com,bsalomon@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/879483003

1 files changed, 21 insertions, 12 deletions

diff --git a/src/core/SkPicture.cpp b/src/core/SkPicture.cpp
index c7e36e7ecd..871a62e8f3 100644
--- a/src/core/SkPicture.cpp
+++ b/src/core/SkPicture.cpp
@@ -239,22 +239,31 @@ SkPicture::Analysis::Analysis(const SkRecord& record) {
 bool SkPicture::Analysis::suitableForGpuRasterization(const char** reason,
                                                       int sampleCount) const {
     // TODO: the heuristic used here needs to be refined
-    static const int kNumSlowPathsTol = 6;
+    static const int kNumPaintWithPathEffectsUsesTol = 1;
+    static const int kNumAAConcavePathsTol = 5;
 
-    int numSlowPathDashedPaths = fNumPaintWithPathEffectUses;
-    if (0 == sampleCount) {
-        // The fast dashing path only works when MSAA is disabled
-        numSlowPathDashedPaths -= fNumFastPathDashEffects;
-    }
-
-    int numSlowPaths = fNumAAConcavePaths - 
-                       fNumAAHairlineConcavePaths -
-                       fNumAADFEligibleConcavePaths;
+    int numNonDashedPathEffects = fNumPaintWithPathEffectUses -
+                                  fNumFastPathDashEffects;
+    bool suitableForDash = (0 == fNumPaintWithPathEffectUses) ||
+                           (numNonDashedPathEffects < kNumPaintWithPathEffectsUsesTol
+                               && 0 == sampleCount);
 
-    bool ret = numSlowPathDashedPaths + numSlowPaths < kNumSlowPathsTol;
+    bool ret = suitableForDash &&
+               (fNumAAConcavePaths - fNumAAHairlineConcavePaths - fNumAADFEligibleConcavePaths)
+                   < kNumAAConcavePathsTol;
 
     if (!ret && reason) {
-        *reason = "Too many slow paths (either concave or dashed).";
+        if (!suitableForDash) {
+            if (0 != sampleCount) {
+                *reason = "Can't use multisample on dash effect.";
+            } else {
+                *reason = "Too many non dashed path effects.";
+            }
+        } else if ((fNumAAConcavePaths - fNumAAHairlineConcavePaths - fNumAADFEligibleConcavePaths)
+                    >= kNumAAConcavePathsTol)
+            *reason = "Too many anti-aliased concave paths.";
+        else
+            *reason = "Unknown reason for GPU unsuitability.";
     }
     return ret;
 }