Notify font loads via FontLoader

Notify font loads via FontLoader

Before this patch, font load was noticed to CSSFontSelector through the
following path:

 RemoteFontFaceSource
 -> CSSFontFace
 -> CSSSegmentedFontFace
 -> CSSFontSelector

However, StyleEngine clears FontFaceCache upon stylesheet changes and
reconstruct it lazily, it is possible that CSSSegmentedFontFace is
absent when a load is completed. As a result, loaded font is not
rendered.

This patch fixes the problem by changing the notification path as follows:
 RemoteFontFaceSource -> FontLoader -> CSSFontSelector.

BUG=378238
TEST=fast/css/font-face-css-change-while-loading.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=176463

[bashi, 2014-06-18 07:27:45]

non-owner LGTM.

https://codereview.chromium.org/321403003/diff/60001/Source/core/css/FontLoad...
File Source/core/css/FontLoader.cpp (right):

https://codereview.chromium.org/321403003/diff/60001/Source/core/css/FontLoad...
Source/core/css/FontLoader.cpp:75: void FontLoader::clearResourceFetcher()
nit: we might want to rename this method.

[Kunihiko Sakamoto, 2014-06-18 08:21:26]

https://codereview.chromium.org/321403003/diff/60001/Source/core/css/FontLoad...
File Source/core/css/FontLoader.cpp (right):

https://codereview.chromium.org/321403003/diff/60001/Source/core/css/FontLoad...
Source/core/css/FontLoader.cpp:75: void FontLoader::clearResourceFetcher()
On 2014/06/18 07:27:45, bashi1 wrote:
> nit: we might want to rename this method.

Renamed to clearResourceFetcherAndFontSelector (couldn't come up with a good
name...).

[dglazkov, 2014-06-18 14:47:18]

lgtm

[Kunihiko Sakamoto, 2014-06-18 23:44:45]

The CQ bit was checked by ksakamoto@chromium.org

[commit-bot: I haz the power, 2014-06-18 23:45:43]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ksakamoto@chromium.org/321403003/80001

[commit-bot: I haz the power, 2014-06-18 23:49:47]

Change committed as 176463