Media Galleries API Metadata: SafeMediaMetadataParser and IPCTunnelDataReader.

chrome/common/chrome_utility_messages.h

 // Copyright (c) 2012 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.
 
 // Multiply-included message file, so no include guard.
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 209 matching lines @@
 #endif  // defined(OS_WIN) || defined(OS_MACOSX)
 
 #if !defined(OS_ANDROID) && !defined(OS_IOS)
 // Tell the utility process to attempt to validate the passed media file. The
 // file will undergo basic sanity checks and will be decoded for up to
 // |milliseconds_of_decoding| wall clock time. It is still not safe to decode
 // the file in the browser process after this check.
 IPC_MESSAGE_CONTROL2(ChromeUtilityMsg_CheckMediaFile,
                      int64 /* milliseconds_of_decoding */,
                      IPC::PlatformFileForTransit /* Media file to parse */)
+
+IPC_MESSAGE_CONTROL2(
+    ChromeUtilityMsg_ParseMediaMetadata,
+    std::string /* mime_type */,
+    int64 /* total_size */)
+
+IPC_MESSAGE_CONTROL2(
+    ChromeUtilityMsg_ParseMediaMetadata_RequestBlobBytes_Finished,
+    int64 /* request_id */,
+    std::string /* bytes */)

[vandebo (ex-Chrome), 2014/01/07 18:34:59]

Maybe this should be char* instead of std::string? The data isn't a string and
base::File::Read() uses char* to return data.

[tommycli, 2014/01/07 20:23:31]

I don't see any other pointers in IPC messages. I do see std::vector<unsigned
char>, but that seems worse. I need the length in any case...

[vandebo (ex-Chrome), 2014/01/08 00:26:18]

I think it's preferred to pass std::vector<unsigned char> and length. 
std::string should be used for strings.

[tommycli, 2014/01/08 01:17:10]

Done.

 #endif  // !defined(OS_ANDROID) && !defined(OS_IOS)
 
 //------------------------------------------------------------------------------
 // Utility process host messages:
 // These are messages from the utility process to the browser.
 
 // Reply when the utility process is done unpacking an extension.  |manifest|
 // is the parsed manifest.json file.
 // The unpacker should also have written out files containing the decoded
 // images and message catalogs from the extension. The data is written into a
@@ skipping 125 matching lines @@
 // the INI files in Picasa Folders.
 IPC_MESSAGE_CONTROL1(ChromeUtilityHostMsg_IndexPicasaAlbumsContents_Finished,
                      picasa::AlbumImagesMap /* albums_images */)
 #endif  // defined(OS_WIN) || defined(OS_MACOSX)
 
 #if !defined(OS_ANDROID) && !defined(OS_IOS)
 // Reply after checking the passed media file. A true result indicates that
 // the file appears to be a well formed media file.
 IPC_MESSAGE_CONTROL1(ChromeUtilityHostMsg_CheckMediaFile_Finished,
                      bool /* passed_checks */)
+
+IPC_MESSAGE_CONTROL2(
+    ChromeUtilityHostMsg_ParseMediaMetadata_Finished,
+    bool /* parse_success */,
+    base::DictionaryValue /* metadata */)
+
+IPC_MESSAGE_CONTROL3(
+    ChromeUtilityHostMsg_ParseMediaMetadata_RequestBlobBytes,
+    int64 /* request_id */,
+    int64 /* start_byte */,
+    int64 /* length */)
 #endif  // !defined(OS_ANDROID) && !defined(OS_IOS)