[filebrowser] More reliable file saving in Photo Editor

chrome/browser/resources/file_manager/js/exif_parser.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 const EXIF_MARK_SOI = 0xffd8;  // Start of image data.
 const EXIF_MARK_SOS = 0xffda;  // Start of "stream" (the actual image data).
 const EXIF_MARK_SOF = 0xffc0;  // Start of "frame"
 const EXIF_MARK_EXIF = 0xffe1;  // Start of exif block.
 
 const EXIF_ALIGN_LITTLE = 0x4949;  // Indicates little endian exif data.
 const EXIF_ALIGN_BIG = 0x4d4d;  // Indicates big endian exif data.
 
 const EXIF_TAG_TIFF = 0x002a;  // First directory containing TIFF data.
 const EXIF_TAG_GPSDATA = 0x8825;  // Pointer from TIFF to the GPS directory.
 const EXIF_TAG_EXIFDATA = 0x8769;  // Pointer from TIFF to the EXIF IFD.
 const EXIF_TAG_SUBIFD = 0x014a;  // Pointer from TIFF to "Extra" IFDs.
 
 const EXIF_TAG_JPG_THUMB_OFFSET = 0x0201;  // Pointer from TIFF to thumbnail.
 const EXIF_TAG_JPG_THUMB_LENGTH = 0x0202;  // Length of thumbnail data.
 
 const EXIF_TAG_ORIENTATION = 0x0112;
 const EXIF_TAG_X_DIMENSION = 0xA002;
 const EXIF_TAG_Y_DIMENSION = 0xA003;
 
 function ExifParser(parent) {
-  MetadataParser.apply(this, [parent]);
-  this.verbose = false;
-  this.mimeType = 'image/jpeg';
+  ImageParser.call(this, parent, 'jpeg', /\.jpe?g$/i);
 }
 
-ExifParser.parserType = 'exif';
-
-ExifParser.prototype = {__proto__: MetadataParser.prototype};
-
-ExifParser.prototype.urlFilter = /\.jpe?g$/i;
+ExifParser.prototype = {__proto__: ImageParser.prototype};
 
 ExifParser.prototype.parse = function(file, callback, errorCallback) {
   var self = this;
   var currentStep = -1;
 
   function nextStep(var_args) {
     self.vlog('exif nextStep: ' + steps[currentStep + 1].name);
     try {
       steps[++currentStep].apply(null, arguments);
     } catch(e) {
@@ skipping 29 matching lines @@
         mark = self.readMark(br);
         if (mark == EXIF_MARK_SOF) {
           // If we reached this section first then there is no EXIF data.
           // Extract image dimensions and return.
 
           // TODO(kaznacheev) Here we are assuming that SOF section lies within
           // first 1024 bytes. This must be true for any normal JPEG file
           // with no EXIF data. Still might want to handle this more carefully.
           if (br.tell() + 7 < buf.byteLength) {
             br.seek(3, ByteReader.SEEK_CUR);
-            var metadata = {mimeType: self.mimeType};
+            var metadata = self.createDefaultMetadata();
             metadata.width = br.readScalar(2);
             metadata.height = br.readScalar(2);
             callback(metadata);
             return;
           }
         }
         if (mark == EXIF_MARK_EXIF) {
           var length = self.readMarkLength(br);
 
           // Offsets inside the EXIF block are based after this bit of
@@ skipping 22 matching lines @@
       if (order == EXIF_ALIGN_LITTLE) {
         br.setByteOrder(ByteReader.LITTLE_ENDIAN);
       } else if (order != EXIF_ALIGN_BIG) {
         return onError('Invalid alignment value: ' + order.toString(16));
       }
 
       var tag = br.readScalar(2);
       if (tag != EXIF_TAG_TIFF)
         return onError('Invalid TIFF tag: ' + tag.toString(16));
 
-      var metadata = {
-        metadataType: ExifParser.parserType,
-        mimeType: self.mimeType,
-        littleEndian: (order == EXIF_ALIGN_LITTLE),
-        ifd: {
-          image: {},
-          thumbnail: {}
-        }
+      var metadata = self.createDefaultMetadata();
+      metadata.littleEndian = (order == EXIF_ALIGN_LITTLE);
+      metadata.ifd = {
+        image: {},
+        thumbnail: {}
       };
       var directoryOffset = br.readScalar(4);
 
       // Image directory.
       self.vlog('Read image directory.');
       br.seek(directoryOffset);
       directoryOffset = self.readDirectory(br, metadata.ifd.image);
       metadata.imageTransform = self.parseOrientation(metadata.ifd.image);
 
       // Thumbnail Directory chained from the end of the image directory.
@@ skipping 208 matching lines @@
     return {
       scaleX: ExifParser.SCALEX[index],
       scaleY: ExifParser.SCALEY[index],
       rotate90: ExifParser.ROTATE90[index]
     }
   }
   return null;
 };
 
 MetadataDispatcher.registerParserClass(ExifParser);