Trim FontSelector interface a bit.

Trim FontSelector interface a bit.

A two-parter:
1) Split off FontCacheClient interface and make FontCache forget about
FontSelector altogether.
2) De-interface font invalidation callback registration/unregisration,
since they are only used in Source/core. This costs us a couple of
static_casts, but overall, it still looks cleaner.

R=ksakamoto@chromium.org,eae
BUG=315783
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=165351

[eae, 2014-01-17 23:13:26]

LGTM

https://codereview.chromium.org/140913011/diff/1/Source/core/html/canvas/Canv...
File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):

https://codereview.chromium.org/140913011/diff/1/Source/core/html/canvas/Canv...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:181:
static_cast<CSSFontSelector*>(m_font.fontSelector())->registerForInvalidationCallbacks(this);
I'm not thrilled about all these casts, I assume they are only needed as a
stop-gap?

[dglazkov, 2014-01-17 23:15:31]

On 2014/01/17 23:13:26, eae wrote:
> LGTM
> 
>
https://codereview.chromium.org/140913011/diff/1/Source/core/html/canvas/Canv...
> File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):
> 
>
https://codereview.chromium.org/140913011/diff/1/Source/core/html/canvas/Canv...
> Source/core/html/canvas/CanvasRenderingContext2D.cpp:181:
>
static_cast<CSSFontSelector*>(m_font.fontSelector())->registerForInvalidationCallbacks(this);
> I'm not thrilled about all these casts, I assume they are only needed as a
> stop-gap?

Yes, trying to remove them next...

[commit-bot: I haz the power, 2014-01-17 23:16:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dglazkov@chromium.org/140913011/1

[commit-bot: I haz the power, 2014-01-18 00:46:11]

Change committed as 165351