Revert "move decal_filter_scale inline, walk decal in 32.32"

This reverts commit 6bee47b.

Reason for revert: needs a Google3 guard.

Original change's description:
> move decal_filter_scale inline, walk decal in 32.32
> 
> Walking soemtimes in 32.32 and sometimes in 16.16 is leading to small
> diffs in https://chromium-review.googlesource.com/c/chromium/src/+/1346729.
> 
> I think by walking either consistently will help avoid the problems.
> Might as well walk 32.32.
> 
> Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
> Change-Id: I4bbe8e10655a97367d3b59d203206bc2c2cf55e8
> Reviewed-on: https://skia-review.googlesource.com/c/172941
> Auto-Submit: Mike Klein <mtklein@google.com>
> Reviewed-by: Mike Klein <mtklein@google.com>
> Commit-Queue: Mike Klein <mtklein@google.com>

TBR=mtklein@google.com,fmalita@chromium.org,reed@google.com

Change-Id: I0e1c3eb1459dd5466c7220623ba3891ab64b9ea8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Reviewed-on: https://skia-review.googlesource.com/c/172943
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>

Author: Mike Klein

src/core/SkBitmapProcState_matrix.h

@@ -41,23 +41,18 @@ void SCALE_FILTER_NAME(const SkBitmapProcState& s,
     }
 
 #ifdef CHECK_FOR_DECAL
-    // TODO: can_truncate_to_fixed_for_decal() is kind of misnamed now that
-    // we're not really stepping in SkFixed (16.16) anymore.
-    if (can_truncate_to_fixed_for_decal(SkFractionalIntToFixed(fx),
-                                        SkFractionalIntToFixed(dx), count, maxX)) {
-        while (count --> 0) {
+    const SkFixed fixedFx = SkFractionalIntToFixed(fx);
+    const SkFixed fixedDx = SkFractionalIntToFixed(dx);
+    if (can_truncate_to_fixed_for_decal(fixedFx, fixedDx, count, maxX)) {
+        decal_filter_scale(xy, fixedFx, fixedDx, count);
+    } else
+#endif
+    {
+        do {
             SkFixed fixedFx = SkFractionalIntToFixed(fx);
-            SkASSERT((fixedFx >> (16 + 14)) == 0);
-            *xy++ = (fixedFx >> 12 << 14) | ((fixedFx >> 16) + 1);
+            *xy++ = pack(fixedFx, maxX, s.fFilterOneX);
             fx += dx;
-        }
-        return;
-    }
-#endif
-    while (count --> 0) {
-        SkFixed fixedFx = SkFractionalIntToFixed(fx);
-        *xy++ = pack(fixedFx, maxX, s.fFilterOneX);
-        fx += dx;
+        } while (--count != 0);
     }
 }
 

src/core/SkBitmapProcState_matrixProcs.cpp

@@ -303,6 +303,14 @@ static void nofilter_scale(const SkBitmapProcState& s,
     #include "SkBitmapProcState_matrix_neon.h"
 
 #else
+    static void decal_filter_scale(uint32_t dst[], SkFixed fx, SkFixed dx, int count) {
+        while (count --> 0) {
+            SkASSERT((fx >> (16 + 14)) == 0);
+            *dst++ = (fx >> 12 << 14) | ((fx >> 16) + 1);
+            fx += dx;
+        }
+    }
+
     static unsigned clamp(SkFixed fx, int max) {
         return SkClampMax(fx >> 16, max);
     }