Remove SkEncodedInfo kUnknown_Color and kUnknown_Alpha from public API

src/codec/SkWebpCodec.cpp

Index: src/codec/SkWebpCodec.cpp
diff --git a/src/codec/SkWebpCodec.cpp b/src/codec/SkWebpCodec.cpp
index e40c3f237792fa38454f72c1fb2d5f2e150ae672..883930b5c6cc6ee4b41ebd621e94b8182f13a712 100644
--- a/src/codec/SkWebpCodec.cpp
+++ b/src/codec/SkWebpCodec.cpp
@@ -31,7 +31,7 @@ bool SkWebpCodec::IsWebp(const void* buf, size_t bytesRead) {
 // Parse headers of RIFF container, and check for valid Webp (VP8) content.
 // NOTE: This calls peek instead of read, since onGetPixels will need these
 // bytes again.
-static bool webp_parse_header(SkStream* stream, int* width, int* height, SkEncodedInfo* info) {
+bool SkWebpCodec::ReadHeader(SkStream* stream, SkCodec** outCodec) {
     unsigned char buffer[WEBP_VP8_HEADER_SIZE];
     SkASSERT(WEBP_VP8_HEADER_SIZE <= SkCodec::MinBufferedBytesNeeded());
 
@@ -61,7 +61,7 @@ static bool webp_parse_header(SkStream* stream, int* width, int* height, SkEncod
         }
     }
 
-    if (info) {
+    if (outCodec) {
         SkEncodedInfo::Color color;
         SkEncodedInfo::Alpha alpha;
         switch (features.format) {
@@ -98,19 +98,20 @@ static bool webp_parse_header(SkStream* stream, int* width, int* height, SkEncod
                 return false;
         }
 
-        *width = features.width;
-        *height = features.height;
-        *info = SkEncodedInfo::Make(color, alpha, 8);
+        SkEncodedInfo info = SkEncodedInfo::Make(color, alpha, 8);
+        *outCodec = new SkWebpCodec(features.width, features.height, info, stream);
     }
     return true;
 }
 
 SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
     SkAutoTDelete<SkStream> streamDeleter(stream);
-    int width, height;
-    SkEncodedInfo info;
-    if (webp_parse_header(stream, &width, &height, &info)) {
-        return new SkWebpCodec(width, height, info, streamDeleter.release());
+    SkCodec* outCodec;
+    if (SkWebpCodec::ReadHeader(stream, &outCodec)) {

[scroggo, 2016/04/25 15:10:43]

Since ReadHeader is used only in this method, I don't see any reason to separate
the two. I would delete this method entirely, and repurpose webp_parse_header
into NewFromStream.

[msarett, 2016/04/25 15:18:21]

Of course, that's much better :).

+        // Codec has taken ownership of the stream.
+        SkASSERT(outCodec);
+        streamDeleter.release();
+        return outCodec;
     }
     return nullptr;
 }