Unexpected mime type should be a ConversionException.

Author: rjrjr

retrofit-converters/wire/src/main/java/retrofit/converter/WireConverter.java

@@ -37,7 +37,7 @@ public WireConverter(Wire wire) {
     }
 
     if (!MIME_TYPE.equalsIgnoreCase(body.mimeType())) {
-      throw new IllegalArgumentException("Expected a proto but was: " + body.mimeType());
+      throw new ConversionException("Expected a proto but was: " + body.mimeType());
     }
 
     InputStream in = null;

retrofit-converters/wire/src/test/java/retrofit/converter/WireConverterTest.java

@@ -64,7 +64,7 @@ public final class WireConverterTest {
     try {
       converter.fromBody(decodeBase64("////", "yummy/bytes"), Person.class);
       fail();
-    } catch (IllegalArgumentException e) {
+    } catch (ConversionException e) {
       assertThat(e).hasMessage("Expected a proto but was: yummy/bytes");
     }
   }