[Android] Use 1/4 scale low resolution tiles on high-res devices

[Android] Use 1/4 scale low resolution tiles on high-res devices

If a device has a screen with a high enough resolution for us to start
using 512x512 tiles, use 1/4 scale low resolution tiles instead of 1/8
ones. This makes page content -- especially text -- look less fuzzy
while scrolling.

BUG=175976

[Sami, 2013-02-20 15:29:08]

This version enables 1/4 res tiles on devices where we use 512x512 tiles.

[Tom Hudson, 2013-02-20 15:56:49]

LGTM

[klobag.chromium, 2013-02-20 16:38:22]

https://codereview.chromium.org/12314013/diff/1/content/renderer/gpu/render_w...
File content/renderer/gpu/render_widget_compositor.cc (right):

https://codereview.chromium.org/12314013/diff/1/content/renderer/gpu/render_w...
content/renderer/gpu/render_widget_compositor.cc:134: const int
kMinSlowDownScaleFactor = 0;
Shouldn't min be 1? 0 as a scale factor seems dangerous.

[Sami, 2013-02-20 16:45:14]

https://codereview.chromium.org/12314013/diff/1/content/renderer/gpu/render_w...
File content/renderer/gpu/render_widget_compositor.cc (right):

https://codereview.chromium.org/12314013/diff/1/content/renderer/gpu/render_w...
content/renderer/gpu/render_widget_compositor.cc:134: const int
kMinSlowDownScaleFactor = 0;
On 2013/02/20 16:38:22, klobag.chromium wrote:
> Shouldn't min be 1? 0 as a scale factor seems dangerous.

It's defined so that a factor of 0 means we skip the slowdown code completely.
Right now it's pretty much the same as setting a factor of 1 except that a
slightly different code path is used.

See how this factor is used at
https://code.google.com/searchframe#OAMlx_jo-ck/src/cc/picture_pile_impl.cc&e...

[nduca, 2013-02-20 17:55:44]

your'e mixing and matching terms here. 4 isn't a factor, 0.25 is a factor. Pass
0.25 or change the meaning in cc

[nduca, 2013-03-13 06:03:07]

Should we close this?

[Sami (do not use), 2013-03-13 10:28:48]

Yup, done.


On 13 March 2013 06:03, <nduca@chromium.org> wrote:

> Should we close this?
>
>
https://codereview.chromium.**org/12314013/<https://codereview.chromium.org/1...
>