Adjust the alpha type for pixelRefs.

src/core/SkBitmap.cpp

Index: src/core/SkBitmap.cpp
diff --git a/src/core/SkBitmap.cpp b/src/core/SkBitmap.cpp
index 0490e8f4827aafefc5da8680936fa4599a233093..b58c08ace32d58337ae2dcbc5e6539cf90f8aced 100644
--- a/src/core/SkBitmap.cpp
+++ b/src/core/SkBitmap.cpp
@@ -150,42 +150,11 @@ void SkBitmap::getBounds(SkIRect* bounds) const {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-static bool validate_alphaType(SkColorType colorType, SkAlphaType alphaType,
-                               SkAlphaType* canonical = NULL) {
-    switch (colorType) {
-        case kUnknown_SkColorType:
-            alphaType = kIgnore_SkAlphaType;
-            break;
-        case kAlpha_8_SkColorType:
-            if (kUnpremul_SkAlphaType == alphaType) {
-                alphaType = kPremul_SkAlphaType;
-            }
-            // fall-through
-        case kIndex_8_SkColorType:
-        case kARGB_4444_SkColorType:
-        case kRGBA_8888_SkColorType:
-        case kBGRA_8888_SkColorType:
-            if (kIgnore_SkAlphaType == alphaType) {
-                return false;
-            }
-            break;
-        case kRGB_565_SkColorType:
-            alphaType = kOpaque_SkAlphaType;
-            break;
-        default:
-            return false;
-    }
-    if (canonical) {
-        *canonical = alphaType;
-    }
-    return true;
-}
-
 bool SkBitmap::setInfo(const SkImageInfo& origInfo, size_t rowBytes) {
     SkImageInfo info = origInfo;
 
-    if (!validate_alphaType(info.fColorType, info.fAlphaType,
-                            &info.fAlphaType)) {
+    if (!SkValidateAlphaType(info.fColorType, info.fAlphaType,
+                             &info.fAlphaType)) {
         return reset_return_false(this);
     }
 
@@ -226,7 +195,7 @@ bool SkBitmap::setConfig(Config config, int width, int height, size_t rowBytes,
 #endif
 
 bool SkBitmap::setAlphaType(SkAlphaType alphaType) {
-    if (!validate_alphaType(fInfo.fColorType, alphaType, &alphaType)) {
+    if (!SkValidateAlphaType(fInfo.fColorType, alphaType, &alphaType)) {
         return false;
     }
     if (fInfo.fAlphaType != alphaType) {
@@ -1300,7 +1269,7 @@ void SkBitmap::legacyUnflatten(SkReadBuffer& buffer) {
     if (!buffer.validate((info.width() >= 0) && (info.height() >= 0) &&
                          SkColorTypeIsValid(info.fColorType) &&
                          SkAlphaTypeIsValid(info.fAlphaType) &&
-                         validate_alphaType(info.fColorType, info.fAlphaType) &&
+                         SkValidateAlphaType(info.fColorType, info.fAlphaType) &&
                          info.validRowBytes(rowBytes))) {
         return;
     }