Add utility for converting SkCanvas to CGContext

Add utility for converting SkCanvas to CGContext

Skia on Mac uses Skia to render WebKit, and CG 
to render UI elements. The CG elements need a 
transcribed graphics context that preserves the 
canvas matrix, and the canvas clip. 

The BitLockerSkia utility class sets up a CGContext 
from the SkCanvas, locks the bitmap's bits, and 
releases the lock when the class goes out of scope. 

Each time the CGContext is retrieved, it is rebuilt. 
This permits the caller to modify the same canvas 
between calls. 

Outside of the unit test, there are no callers
to this utility for now.

BUG=79463
TEST=SkiaUtilsMacTest.*

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=85692

[Nico, 2011-05-16 15:13:00]

LGTM

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.h
File skia/ext/skia_utils_mac.h (right):

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.h#newco...
skia/ext/skia_utils_mac.h:92: public:
indent 1

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.h#newco...
skia/ext/skia_utils_mac.h:97: private:
indent 1

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.h#newco...
skia/ext/skia_utils_mac.h:99: SkCanvas* m_canvas;
we name members canvas_, not m_canvas. same in the next line.

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.mm
File skia/ext/skia_utils_mac.mm (right):

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.mm#newc...
skia/ext/skia_utils_mac.mm:292: , m_cgContext(0) {
, goes on previous line

[_cary, 2011-05-16 15:58:01]

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.h
File skia/ext/skia_utils_mac.h (right):

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.h#newco...
skia/ext/skia_utils_mac.h:92: public:
On 2011/05/16 15:13:00, Nico wrote:
> indent 1

Done.

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.h#newco...
skia/ext/skia_utils_mac.h:97: private:
On 2011/05/16 15:13:00, Nico wrote:
> indent 1

Done.

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.h#newco...
skia/ext/skia_utils_mac.h:99: SkCanvas* m_canvas;
On 2011/05/16 15:13:00, Nico wrote:
> we name members canvas_, not m_canvas. same in the next line.

Done.

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.mm
File skia/ext/skia_utils_mac.mm (right):

http://codereview.chromium.org/7031006/diff/1/skia/ext/skia_utils_mac.mm#newc...
skia/ext/skia_utils_mac.mm:292: , m_cgContext(0) {
On 2011/05/16 15:13:00, Nico wrote:
> , goes on previous line

Done.

[commit-bot: I haz the power, 2011-05-17 23:06:13]

Change committed as 85692