NaCl SDK: Demonstrate use of pp::Graphics2D::SetScale()

NaCl SDK: Demonstrate use of pp::Graphics2D::SetScale()

Demonstrate in the NaCl SDK API demo for pp::Graphics2D how
to use full device resolution on HiDPI displays. For Graphics2D,
the example now calls pp::View::GetDeviceScale(), and creates
a Graphics 2D context with the correct number of pixels, as well
as show when to call pp::Graphics2D::SetScale().

It also scales the mouse position to the correct location and
increases the radius of the circle created in DrawMouse() to match.

BUG=144071, 392557
TEST=Build NaCl SDK, run with --force-device-scale-factor=2

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=283832

[Josh Horwich, 2014-07-17 00:07:34]

PTAL

[binji, 2014-07-17 00:11:38]

thanks, lgtm

https://codereview.chromium.org/397173003/diff/1/native_client_sdk/src/exampl...
File native_client_sdk/src/examples/api/graphics_2d/graphics_2d.cc (right):

https://codereview.chromium.org/397173003/diff/1/native_client_sdk/src/exampl...
native_client_sdk/src/examples/api/graphics_2d/graphics_2d.cc:192: int radius =
kMouseRadius * device_scale_;
no warning here about truncating from float to int?

[Josh Horwich, 2014-07-17 00:20:58]

https://codereview.chromium.org/397173003/diff/1/native_client_sdk/src/exampl...
File native_client_sdk/src/examples/api/graphics_2d/graphics_2d.cc (right):

https://codereview.chromium.org/397173003/diff/1/native_client_sdk/src/exampl...
native_client_sdk/src/examples/api/graphics_2d/graphics_2d.cc:192: int radius =
kMouseRadius * device_scale_;
On 2014/07/17 00:11:38, binji wrote:
> no warning here about truncating from float to int?

I haven't seen any (here, and the pp::Size / pp::Point constructors that take
int's/int32_t's).

[Josh Horwich, 2014-07-17 17:49:28]

The CQ bit was checked by jhorwich@chromium.org

[commit-bot: I haz the power, 2014-07-17 17:50:32]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jhorwich@chromium.org/397173003/1

[commit-bot: I haz the power, 2014-07-17 19:09:50]

Change committed as 283832