Fix CopyFromBackingStore when there's no cg_layer_.

Fix CopyFromBackingStore when there's no cg_layer_.

In CopyFromBackingStore use the cg_bitmap_ as the source in case cg_layer_
hasn't been created yet.

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=209399

[Nico, 2013-06-28 19:30:02]

lgtm

This isn't right for hidpi screens, but neither is the current code.

[msimonides, 2013-07-01 06:40:20]

On 2013/06/28 19:30:02, Nico wrote:
> lgtm
> 
> This isn't right for hidpi screens, but neither is the current code.

What would be needed to also handles the hidpi screens?

[commit-bot: I haz the power, 2013-07-01 06:41:30]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/msimonides@opera.com/18052011/1

[commit-bot: I haz the power, 2013-07-01 08:28:22]

Change committed as 209399

[Nico, 2013-07-01 16:54:59]

https://codereview.chromium.org/18052011/diff/1/content/browser/renderer_host...
File content/browser/renderer_host/backing_store_mac.mm (right):

https://codereview.chromium.org/18052011/diff/1/content/browser/renderer_host...
content/browser/renderer_host/backing_store_mac.mm:165: bool
BackingStoreMac::CopyFromBackingStore(const gfx::Rect& rect,
for hidpi: one probably would hand in a scale factor output is desired in too
(or hand it out if this always uses the backing store's scale factor), then
allocate the output at pixel size rect * scale, and apply a scale to
temp_context if necessary.

https://codereview.chromium.org/18052011/diff/1/content/browser/renderer_host...
content/browser/renderer_host/backing_store_mac.mm:173:
CGContextTranslateCTM(temp_context, 0.0, size().height());
size() returns logical size, which isn't right for mirroring in y. This should
probably use rect.height() instead, possibly scaled by the output scale factor
if necessary (if the output scale factor is different from the backing store's).