Revert of correct reporting of kAlphaUnchanged_Flag in ModeFilter

src/effects/SkColorFilters.cpp

Index: src/effects/SkColorFilters.cpp
diff --git a/src/effects/SkColorFilters.cpp b/src/effects/SkColorFilters.cpp
index d4723ec18f6057623110a4e0a568f2da1e3398e7..8bcd0ebc5d67d96acf3d94149a744e30fd23f292 100644
--- a/src/effects/SkColorFilters.cpp
+++ b/src/effects/SkColorFilters.cpp
@@ -27,18 +27,7 @@
 }
 
 uint32_t SkModeColorFilter::getFlags() const {
-    uint32_t flags = 0;
-    switch (fMode) {
-        case SkXfermode::kDst_Mode:      //!< [Da, Dc]
-        case SkXfermode::kSrcATop_Mode:  //!< [Da, Sc * Da + (1 - Sa) * Dc]
-            flags |= kAlphaUnchanged_Flag;
-        default:
-            break;
-    }
-    if (fProc16) {
-        flags |= kHasFilter16_Flag;
-    }
-    return flags;
+    return fProc16 ? (kAlphaUnchanged_Flag | kHasFilter16_Flag) : 0;
 }
 
 void SkModeColorFilter::filterSpan(const SkPMColor shader[], int count, SkPMColor result[]) const {
@@ -401,7 +390,7 @@
 
     uint32_t getFlags() const SK_OVERRIDE {
         if (SkGetPackedA32(this->getPMColor()) == 0xFF) {
-            return kHasFilter16_Flag;
+            return kAlphaUnchanged_Flag | kHasFilter16_Flag;
         } else {
             return 0;
         }
@@ -431,7 +420,7 @@
 
     uint32_t getFlags() const SK_OVERRIDE {
         if (SkGetPackedA32(this->getPMColor()) == 0xFF) {
-            return kHasFilter16_Flag;
+            return kAlphaUnchanged_Flag | kHasFilter16_Flag;
         } else {
             return 0;
         }