VideoPlayer not working on html export

[guilhermefelipecgs]

Godot version:
3.0.3

OS/device including version:
Firefox 60.0.2

Issue description:
I can't play webm and ogv files on web.

This error happens when I tried play a webm file:

Init OS
Init Audio
Init VS
Init Physicsserver
OpenGL ES 3.0 Renderer: Mozilla
**ERROR**: Failed loading resource: 'res://Temperature1.webm';
**ERROR**:    At: modules/webm/video_stream_webm.cpp:56:MkvReader() - Condition ' !file ' is true.

And with ogv:

Init OS
Init Audio
Init VS
Init Physicsserver
OpenGL ES 3.0 Renderer: Mozilla
**ERROR**: Condition ' !ti ' is true. returned: StringName()
**ERROR**:    At: core/class_db.cpp:331:get_parent_class() - Condition ' !ti ' is true. returned: StringName()
**ERROR**: No loader found for resource: res://.import/temp1.ogv-ab81cabbdb166e0488226ae04fa42a3a.ogvstr
**ERROR**:    At: core/io/resource_loader.cpp:186:_load() - Method/Function Failed, returning: RES()
**ERROR**: Failed loading resource: res://temp1.ogv
**ERROR**:    At: core/io/resource_loader.cpp:186:_load() - Method/Function Failed, returning: RES()
**ERROR**: **WARNING**: Couldn't load external resource: res://temp1.ogv
**ERROR**:    At: scene/resources/scene_format_text.cpp:174:_parse_ext_resource() - Couldn't load external resource: res://temp1.ogv

Steps to reproduce:
Downlaod the project below and run in browser.

Minimal reproduction project:
Bug Video Player.zip

[guilhermefelipecgs]

Maybe duplicate of #14954?

[leonkrause]

Yes, as detailed in that thread, neither WebM nor Theora files are currently included when exporting.
Closing as duplicate of #14954