Set sRGB flag for PNGs with an sRGB chunk

src/codec/SkCodecPriv.h

Index: src/codec/SkCodecPriv.h
diff --git a/src/codec/SkCodecPriv.h b/src/codec/SkCodecPriv.h
index fa7d146d1afd01ba7c2e3ba3886b48b6367fe999..235c4e24aff3bcbc56787487824170c33f6fd4fa 100644
--- a/src/codec/SkCodecPriv.h
+++ b/src/codec/SkCodecPriv.h
@@ -117,7 +117,12 @@ inline bool valid_alpha(SkAlphaType dstAlpha, SkAlphaType srcAlpha) {
  * - otherwise match the src color type
  */
 inline bool conversion_possible(const SkImageInfo& dst, const SkImageInfo& src) {
-    if (dst.profileType() != src.profileType()) {
+    // FIXME: skbug.com/4895
+    // Currently, we treat both kLinear and ksRGB encoded images as if they are kLinear.
+    // This makes sense while we do not have proper support for ksRGB.  This is also
+    // the reason why we always allow the client to request kLinear.
+    if (dst.profileType() != src.profileType() &&
+            kLinear_SkColorProfileType != dst.profileType()) {
         return false;
     }