Don't load all bytes of video when generating thumbnails.

Don't load all bytes of video when generating thumbnails.

Previously ImageLoader loaded all bytes of video by using XHR before
generating thumbnails. The CL fixes it so that ImageLoader assign entry
URL to video tag directly, which avoids from loading all bytes to
memory.

BUG=597243
TEST=manually

Review URL: https://codereview.chromium.org/1842313005

Cr-Commit-Position: refs/heads/master@{#384515}
(cherry picked from commit 5d9ebe5481791288b7dd28bc51aa608de3e101a9)

Committed: https://chromium.googlesource.com/chromium/src/+/72d9e1dfd3164a33424de724465449924dc6dbf3

[hirono, 2016-04-04 03:57:29]

Description was changed from

==========
Don't load all bytes of video when generating thumbnails.

Previously ImageLoader loaded all bytes of video by using XHR before
generating thumbnails. The CL fixes it so that ImageLoader assign entry
URL to video tag directly, which avoids from loading all bytes to
memory.

BUG=597243
TEST=manually

Review URL: https://codereview.chromium.org/1842313005

Cr-Commit-Position: refs/heads/master@{#384515}
(cherry picked from commit 5d9ebe5481791288b7dd28bc51aa608de3e101a9)
==========

to

==========
Don't load all bytes of video when generating thumbnails.

Previously ImageLoader loaded all bytes of video by using XHR before
generating thumbnails. The CL fixes it so that ImageLoader assign entry
URL to video tag directly, which avoids from loading all bytes to
memory.

BUG=597243
TEST=manually

Review URL: https://codereview.chromium.org/1842313005

Cr-Commit-Position: refs/heads/master@{#384515}
(cherry picked from commit 5d9ebe5481791288b7dd28bc51aa608de3e101a9)

Committed:
https://chromium.googlesource.com/chromium/src/+/72d9e1dfd3164a33424de7244654...
==========

[hirono, 2016-04-04 03:57:32]

Committed patchset #1 (id:1) manually as
72d9e1dfd3164a33424de724465449924dc6dbf3.