Fix invalid static_cast in GpuTileTaskWorkerPool

CFI: fix invalid type cast from base class (Task) to a subclass (RenderTask),
where the actual type is a subclass of TileTask.

This bug has been found with the help of CFI (Control Flow Integrity) checker,
see https://sites.google.com/a/chromium.org/dev/developers/testing/control-flow-integrity

BUG=chromium:457523, chromium:513021
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Committed: https://crrev.com/2f619dc3d4ae84497d440e999296483ef87fa6fd
Cr-Commit-Position: refs/heads/master@{#340010}

[vmpstr, 2015-07-22 22:43:48]

vmpstr@chromium.org changed reviewers:
+ vmpstr@chromium.org

[vmpstr, 2015-07-22 22:43:48]

Can you make the title be 72-col? Maybe put more in the description and just
have

Fix invalid static_cast in GpuRasterWorkerPool

as the subject

https://codereview.chromium.org/1248923002/diff/1/cc/raster/gpu_tile_task_wor...
File cc/raster/gpu_tile_task_worker_pool.cc (right):

https://codereview.chromium.org/1248923002/diff/1/cc/raster/gpu_tile_task_wor...
cc/raster/gpu_tile_task_worker_pool.cc:219: TileTask* raster_task =
static_cast<TileTask*>(task.get());
can you rename raster_task to tile_task as well?

[krasin, 2015-07-22 22:45:06]

Done

[krasin, 2015-07-22 22:50:03]

Please, take another look.

https://codereview.chromium.org/1248923002/diff/1/cc/raster/gpu_tile_task_wor...
File cc/raster/gpu_tile_task_worker_pool.cc (right):

https://codereview.chromium.org/1248923002/diff/1/cc/raster/gpu_tile_task_wor...
cc/raster/gpu_tile_task_worker_pool.cc:219: TileTask* raster_task =
static_cast<TileTask*>(task.get());
On 2015/07/22 22:43:48, vmpstr wrote:
> can you rename raster_task to tile_task as well?

Done.

[vmpstr, 2015-07-22 23:03:02]

lgtm, thanks.

[krasin, 2015-07-22 23:03:31]

The CQ bit was checked by krasin@google.com

[krasin, 2015-07-22 23:03:46]

Thank you for the fast review!

[commit-bot: I haz the power, 2015-07-22 23:06:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1248923002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1248923002/20001

[commit-bot: I haz the power, 2015-07-23 00:34:23]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-23 00:35:13]

Patchset 2 (id:??) landed as
https://crrev.com/2f619dc3d4ae84497d440e999296483ef87fa6fd
Cr-Commit-Position: refs/heads/master@{#340010}