Update use of SkCanvas and SkDevice to match change in Skia

Update use of SkCanvas and SkDevice to match change in Skia:

Refactor SkCanvas so that backends don't need to override it - instead take a device factory class. see: http://codereview.appspot.com/2103045/

BUG=New Skia devices required a corresponding canvas
TEST=None

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=62813

[vandebo (ex-Chrome), 2010-10-01 21:39:03]

This is basically just a Skia cleanup, so spreading the review load, feel free
to bounce to a different reviewer.  I'm holding off committing to Skia in case
any feedback applies to that change as well.

[Evan Martin, 2010-10-04 19:09:47]

I am happy to rubber stamp this, but perhaps it would be good to find a person
closer to this code to review

[vandebo (ex-Chrome), 2010-10-04 19:37:21]

I wasn't particularly looking for a rubber stamp.  Do you have any reviewer
suggestions?

[Evan Martin, 2010-10-04 20:17:17]

On 2010/10/04 19:37:21, vandebo wrote:
> I wasn't particularly looking for a rubber stamp.  Do you have any reviewer
> suggestions?

Who reviewed the Skia change?

(I think I wouldn't have thought you were looking for a rubber stamp if the
review description said what the change did.)

[vandebo (ex-Chrome), 2010-10-04 20:43:13]

I updated the description to be a bit more verbose.  I had Mike Reed review the
Skia change because he suggested it, but not a Chromium committer afaik.

[Evan Martin, 2010-10-04 20:49:05]

LGTM

http://codereview.chromium.org/3590011/diff/1/9
File skia/ext/platform_canvas.h (right):

http://codereview.chromium.org/3590011/diff/1/9#newcode22
skia/ext/platform_canvas.h:22: // transparency: this will enable some
optimizations.
I guess this comment belongs over L26.

[vandebo (ex-Chrome), 2010-10-14 17:40:15]

http://codereview.chromium.org/3590011/diff/1/9
File skia/ext/platform_canvas.h (right):

http://codereview.chromium.org/3590011/diff/1/9#newcode22
skia/ext/platform_canvas.h:22: // transparency: this will enable some
optimizations.
On 2010/10/04 20:49:05, Evan Martin wrote:
> I guess this comment belongs over L26.

Done.

[Safari, 2010-10-17 12:20:16]

it does not compile.

  CXX(target)
out/Release/obj.target/skia/skia/ext/bitmap_platform_device_linux.o
In file included from ./skia/ext/bitmap_platform_device.h:17:0,
                 from skia/ext/bitmap_platform_device.cc:5:
./skia/ext/bitmap_platform_device_linux.h:46:68: error: expected class-name
before ‘{’ token
./skia/ext/bitmap_platform_device_linux.h:88:11: error: ‘SkDeviceFactory’ does
not name a type
make: *** [out/Release/obj.target/skia/skia/ext/bitmap_platform_device.o] Error
1