skia/ext: Remove unused SkFontHost.h include from image_operations.cc

skia/ext: Remove unused SkFontHost.h include from image_operations.cc

Basically SkFontHost is deprecated and SkPixelGeometry should be used
when possible, but since nothing in ImageOperations is using it, removed
this unused include.

BUG=None
TEST=compiles
TBR=reed@google.com

Committed: https://crrev.com/7bf28cfe8fe0385091d37d7382ad28ac67b88f76
Cr-Commit-Position: refs/heads/master@{#309385}

[tfarina, 2014-12-22 01:16:00]

TBRing...

[tfarina, 2014-12-22 01:16:12]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2014-12-22 01:16:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/817913003/1

[tfarina, 2014-12-22 01:25:47]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2014-12-22 01:25:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/817913003/1

[commit-bot: I haz the power, 2014-12-22 02:50:18]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-12-22 02:51:09]

Patchset 1 (id:??) landed as
https://crrev.com/7bf28cfe8fe0385091d37d7382ad28ac67b88f76
Cr-Commit-Position: refs/heads/master@{#309385}