Oilpan: Replace blink_gc_plugin_dump_graph with a more general blink_gc_plugin_flags GYP variable.

Oilpan: Replace blink_gc_plugin_dump_graph with a more general blink_gc_plugin_flags GYP variable.

This allows developers to pass any combination of plugin flags
without modifying the existing GYP setup. For example,
GYP_DEFINES+="blink_gc_plugin_flags='dump-graph=1 warn-raw-ptr=1'"
will enable both graph dumps and raw-pointer warnings.

R=haraken@chromium.org
BUG=334149
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=181734

[haraken, 2014-09-09 10:28:13]

LGTM

[zerny-chromium, 2014-09-09 10:31:28]

zerny@chromium.org changed reviewers:
+ tkent@chromium.org

[zerny-chromium, 2014-09-09 10:31:28]

tkent@ could you do the owner review?

[zerny-chromium, 2014-09-09 10:32:12]

Chrome side plugin change: https://codereview.chromium.org/551343002/

[tkent, 2014-09-09 22:50:24]

lgtm

[zerny-chromium, 2014-09-10 13:26:19]

The CQ bit was checked by zerny@chromium.org

[commit-bot: I haz the power, 2014-09-10 13:26:49]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/zerny@chromium.org/551343003/1

[commit-bot: I haz the power, 2014-09-10 14:29:28]

Committed patchset #1 (id:1) as 181734