Implement ChromeOS mime type extension mappings.

net/base/platform_mime_util_linux.cc

Index: net/base/platform_mime_util_linux.cc
diff --git a/net/base/platform_mime_util_linux.cc b/net/base/platform_mime_util_linux.cc
index ff7f79b1549fe81313df94c66e572f0a5b739926..96b29fac23042ef3859d3c3a9e84e5b53684b2a2 100644
--- a/net/base/platform_mime_util_linux.cc
+++ b/net/base/platform_mime_util_linux.cc
@@ -22,6 +22,8 @@ bool PlatformMimeUtil::GetPlatformMimeTypeFromExtension(
     const base::FilePath::StringType& ext, std::string* result) const {
   return android::GetMimeTypeFromExtension(ext, result);
 }
+#elif defined(OS_CHROMEOS)

[eroman, 2015/05/15 09:05:33]

Actually, I think we need to remove this file from the build when built with
chromeos. Otherwise we will end up with duplicate definitions for
PlatformMimeUtil

[yawano, 2015/05/15 09:19:50]

_linux.cc is included in chromeos build. Changing a gypi file not to include
_linux.cc but to include _chromeos.cc seems to be a big change for me.

How about to do a same thing with OS_ANDROID? i.e. Implement
chromeos::GetMimTypeFromExtension in mime_type_extension_chromeos.cc.

[eroman, 2015/05/18 01:00:08]

Yes that sounds like a good approach (use the same strategy as Android)

[yawano, 2015/05/18 08:59:44]

Done.

+// Implemented in platform_mime_util_chromeos.cc.
 #else
 bool PlatformMimeUtil::GetPlatformMimeTypeFromExtension(
     const base::FilePath::StringType& ext, std::string* result) const {