[Metadata] Fixes for implementation

[Verification] Code works as expected by documentation, fixed crash
when calling api without arguments. Verified in chrome console

Change-Id: I80a021d1804d2b0ac55279df1d3d4cc699bc0a8b

diff --git a/src/metadata/metadata_api.js b/src/metadata/metadata_api.js
index 6126c4a22e2702ceb5d7a1e43f2cd5d6bcee7bff..62790de9b3c8ed3bfa5d6027574d4cf805939777 100755 (executable)
--- a/src/metadata/metadata_api.js
+++ b/src/metadata/metadata_api.js
@@ -19,6 +19,8 @@ var validator_ = privUtils_.validator;
 var types_ = validator_.Types;
 var native_ = new xwalk.utils.NativeManager(extension);
 
+var DEFAULT_BLOB_MIME_TYPE = "image/jpeg"
+
 var MetadataType = {
     ALBUM: 'ALBUM',
     ALBUM_ARTIST: 'ALBUM_ARTIST',
@@ -170,7 +172,7 @@ MetadataFileHandle.prototype.getThumbnailFrame = function() {
     }
     var encodedData = StringToArray(native_.getResultObject(result), Uint8Array);
 
-    return new Blob([encodedData]);
+    return new Blob([encodedData], { type: DEFAULT_BLOB_MIME_TYPE });
 };
 
 MetadataFileHandle.prototype.getFrameAtTime = function() {
@@ -183,7 +185,7 @@ MetadataFileHandle.prototype.getFrameAtTime = function() {
         uri: this.uri,
         id: this._id,
         timestamp: args.timestamp,
-        isAccurate: args.isAccurate
+        isAccurate: args.isAccurate == true // this attribute is optional (false by default)
     };
 
     var result = native_.callSync('MetadataFileHandleGetFrameAtTime', data);
@@ -192,7 +194,7 @@ MetadataFileHandle.prototype.getFrameAtTime = function() {
     }
     var encodedData = StringToArray(native_.getResultObject(result), Uint8Array);
 
-    return new Blob([encodedData]);
+    return new Blob([encodedData], { type: DEFAULT_BLOB_MIME_TYPE });
 };
 
 MetadataFileHandle.prototype.getSyncLyrics = function() {