clip more cases using the CPU allowing more op merges

In desk_gmail.skp, the clips are marked as AA, but are
actually integer bounds. Check for this case and clip
using the CPU. The big benefit for this is that during op
merging the applied clips are nullptr, which allows many more
cases to merge.

Change-Id: Idd000c325da60767b18e22a20cb4afa1c0dd798f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/335052
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>

Author: herbderby

src/gpu/text/GrTextBlob.cpp

@@ -621,19 +621,29 @@ DirectMaskSubRun::makeAtlasTextOp(const GrClip* clip, const SkMatrixProvider& vi
         // If the SubRun is completely outside, don't add an op for it.
         return {nullptr, nullptr};
     } else if (clip != nullptr) {
-        const GrClip::PreClipResult result = clip->preApply(subRunBounds, GrAA::kNo);
-        if (result.fEffect == GrClip::Effect::kClipped) {
-            if (result.fIsRRect && result.fRRect.isRect() && result.fAA == GrAA::kNo) {
-                // Clip geometrically during onPrepare using clipRect.
-                result.fRRect.getBounds().round(&clipRect);
-                if (clipRect.contains(subRunBounds)) {
-                    // If fully within the clip, then signal no clipping using the empty rect.
-                    clipRect = SkIRect::MakeEmpty();
-                }
+        switch (auto result = clip->preApply(subRunBounds, GrAA::kNo); result.fEffect) {
+            case GrClip::Effect::kClippedOut:
+                // Return nullptr op to indicate no op needed.
+                return {nullptr, nullptr};
+            case GrClip::Effect::kUnclipped:
+                clipRect = SkIRect::MakeEmpty();
                 clip = nullptr;
+                break;
+            case GrClip::Effect::kClipped: {
+                if (result.fIsRRect && result.fRRect.isRect()) {
+                    SkRect r = result.fRRect.rect();
+                    if (result.fAA == GrAA::kNo || GrClip::IsPixelAligned(r)) {
+                        // Clip geometrically during onPrepare using clipRect.
+                        r.round(&clipRect);
+                        if (clipRect.contains(subRunBounds)) {
+                            // If fully within the clip, signal no clipping using the empty rect.
+                            clipRect = SkIRect::MakeEmpty();
+                        }
+                        clip = nullptr;
+                    }
+                }
             }
-        } else if (result.fEffect == GrClip::Effect::kClippedOut) {
-            return {nullptr, nullptr};
+            break;
         }
     }