Fix offscreen rendering on iOS by not assuming that the default window bound framebuffer is 0

Fix offscreen rendering on iOS by not assuming that the default window bound framebuffer is 0

BUG=
R=iansf@google.com

Committed: https://chromium.googlesource.com/external/mojo/+/dc370aa7a579af669d76123d8bd1dffbdc191483

[Chinmay, 2015-06-16 00:56:54]

chinmaygarde@google.com changed reviewers:
+ abarth@chromium.org, iansf@google.com

[iansf, 2015-06-16 01:21:27]

https://codereview.chromium.org/1183213007/diff/1/ui/gl/gl_surface_ios.h
File ui/gl/gl_surface_ios.h (right):

https://codereview.chromium.org/1183213007/diff/1/ui/gl/gl_surface_ios.h#newc...
ui/gl/gl_surface_ios.h:20: unsigned int GetBackingFrameBufferObject() override;
Is there a corresponding change in gl_surface.h that should be included?

unsigned int GetBackingFramebufferObject() { return 0; }

or something like that?

Also, the 'b' in GetBackingFramebufferObject should be lowercase, not uppercase.

[Chinmay, 2015-06-16 01:25:55]

On 2015/06/16 at 01:21:27, iansf wrote:
> https://codereview.chromium.org/1183213007/diff/1/ui/gl/gl_surface_ios.h
> File ui/gl/gl_surface_ios.h (right):
> 
>
https://codereview.chromium.org/1183213007/diff/1/ui/gl/gl_surface_ios.h#newc...
> ui/gl/gl_surface_ios.h:20: unsigned int GetBackingFrameBufferObject()
override;
> Is there a corresponding change in gl_surface.h that should be included?
> 
> unsigned int GetBackingFramebufferObject() { return 0; }
> 
> or something like that?
> 
> Also, the 'b' in GetBackingFramebufferObject should be lowercase, not
uppercase.

`GetBackingFramebufferObject` is already a virtual method on GLSurface:
https://github.com/domokit/mojo/blob/master/ui/gl/gl_surface.h#L83 and
https://github.com/domokit/mojo/blob/master/ui/gl/gl_surface.cc#L195

[iansf, 2015-06-16 16:50:01]

lgtm

lgtm

[Chinmay, 2015-06-16 16:51:42]

Committed patchset #1 (id:1) manually as
dc370aa7a579af669d76123d8bd1dffbdc191483 (presubmit successful).