Add reallyHasAlpha() to SkAndroidCodec

include/codec/SkCodec.h

Index: include/codec/SkCodec.h
diff --git a/include/codec/SkCodec.h b/include/codec/SkCodec.h
index 67ccdb241c3225e35e09ef2b75d1fd60bbd64a6b..b38dcd6953c648ccc7774a71400506033c1c2ddd 100644
--- a/include/codec/SkCodec.h
+++ b/include/codec/SkCodec.h
@@ -286,7 +286,7 @@ public:
      *  FIXME: see skbug.com/3582.
      */
     bool reallyHasAlpha() const {
-        return this->onReallyHasAlpha();
+        return kOpaque_SkAlphaType != this->getInfo().alphaType() && this->onReallyHasAlpha();
     }
 
     /**
@@ -486,7 +486,13 @@ protected:
         return false;
     }
 
-    virtual bool onReallyHasAlpha() const { return false; }
+    virtual bool onReallyHasAlpha() const {
+        // If the image indicates that it does have alpha, by default, we

[scroggo, 2015/12/10 18:45:44]

Maybe add a comment that this is only called if the alpha type is not opaque?
Also, should this comment go outside the method body?

[msarett, 2015/12/10 18:53:30]

Done and yes.

+        // will assume this to be true. Subclasses may override this
+        // function if they intend to verify that the image actually has
+        // alpha.
+        return true;
+    }
 
     /**
      *  If the stream was previously read, attempt to rewind.