Add PPB_PDF API to load scaled image resources

Add PPB_PDF API to load scaled image resources

For HiDPI PDF viewer, add new API to fetch properly-scaled resource for the
target display.

BUG=114674
TEST=Run PDF Viewer on HiDPI screen with HiDPI PDF Viewer flag, view buttons

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=149548

[Josh Horwich, 2012-08-01 17:06:52]

Please take a look

Motivation is to allow access to ImageSkiaRep at correct device_scale for HiDPI
PDF viewer's resource images.

Also, I could replace existing GetResourceImage impl to internal call to new
impl with scale=1.0 - please let me know if you'd prefer I do that at once, or
in a later CL. Doing so would reduce code size and quasi-duplication.

[brettw, 2012-08-01 21:20:51]

https://chromiumcodereview.appspot.com/10836055/diff/1/chrome/renderer/pepper...
File chrome/renderer/pepper/ppb_pdf_impl.cc (right):

https://chromiumcodereview.appspot.com/10836055/diff/1/chrome/renderer/pepper...
chrome/renderer/pepper/ppb_pdf_impl.cc:369: PP_Resource
GetResourceImageForScale(PP_Instance instance_id,
This is mostly copied fromGetResourceImage. I wonder if we can re-implement the
old GetResourceImage to be:
  return GetResourceImageForScale(..., 1.0);
?

[Josh Horwich, 2012-08-01 21:42:36]

On 2012/08/01 21:20:51, brettw wrote:
>
https://chromiumcodereview.appspot.com/10836055/diff/1/chrome/renderer/pepper...
> File chrome/renderer/pepper/ppb_pdf_impl.cc (right):
> 
>
https://chromiumcodereview.appspot.com/10836055/diff/1/chrome/renderer/pepper...
> chrome/renderer/pepper/ppb_pdf_impl.cc:369: PP_Resource
> GetResourceImageForScale(PP_Instance instance_id,
> This is mostly copied fromGetResourceImage. I wonder if we can re-implement
the
> old GetResourceImage to be:
>   return GetResourceImageForScale(..., 1.0);
> ?

Yes, we absolutely can - I even had it that way initially but thought it might
be best to leave that alone right before the branch point (this code path would
then only get used if the experimental flag is set). I'll upload a revised patch
with that done momentarily.

[Josh Horwich, 2012-08-01 21:53:51]

Please take a look.

https://chromiumcodereview.appspot.com/10836055/diff/1/chrome/renderer/pepper...
File chrome/renderer/pepper/ppb_pdf_impl.cc (right):

https://chromiumcodereview.appspot.com/10836055/diff/1/chrome/renderer/pepper...
chrome/renderer/pepper/ppb_pdf_impl.cc:369: PP_Resource
GetResourceImageForScale(PP_Instance instance_id,
On 2012/08/01 21:20:51, brettw wrote:
> This is mostly copied fromGetResourceImage. I wonder if we can re-implement
the
> old GetResourceImage to be:
>   return GetResourceImageForScale(..., 1.0);
> ?

Done.

[brettw, 2012-08-01 22:24:26]

lgtm