Fixes zero division when there are no lines to plot (only one revision in range)

Fixes zero division when there are no lines to plot (only one revision in range)
(SkipBuildbotRuns)
Committed: https://code.google.com/p/skia/source/detail?r=9578

[bungeman-skia, 2013-06-13 03:34:10]

https://codereview.chromium.org/16907003/diff/1/bench/bench_graph_svg.py
File bench/bench_graph_svg.py (right):

https://codereview.chromium.org/16907003/diff/1/bench/bench_graph_svg.py#newc...
bench/bench_graph_svg.py:825: 
I think it would be better to put

# If there is nothing to see, don't try to draw anything.
if w == 0 or h == 0:
    return

here. This is the equivalent of something like rect.isEmpty() and takes care of
all of the cases where we might divide by zero below, and we've already done the
math by this point.

[benchen, 2013-06-13 13:37:11]

Thank you Ben. Done.

https://codereview.chromium.org/16907003/diff/1/bench/bench_graph_svg.py
File bench/bench_graph_svg.py (right):

https://codereview.chromium.org/16907003/diff/1/bench/bench_graph_svg.py#newc...
bench/bench_graph_svg.py:825: 
Great suggestion. This is much more readable and takes care of height. Please
take another look (patch set 2).

On 2013/06/13 03:34:10, bungeman1 wrote:
> I think it would be better to put
> 
> # If there is nothing to see, don't try to draw anything.
> if w == 0 or h == 0:
>     return
> 
> here. This is the equivalent of something like rect.isEmpty() and takes care
of
> all of the cases where we might divide by zero below, and we've already done
the
> math by this point.

[bungeman-skia, 2013-06-13 13:48:40]

lgtm at patch set #2.

[benchen, 2013-06-13 13:53:19]

Committed patchset #2 manually as r9578 (presubmit successful).