Simplifying error recovery in declaration list.

Simplifying error recovery in declaration list.

Now declaration handles all errors (instead of splitting error hendling among declaration, delaration_list and decl_list).

Changed error message when syntax error appear in a property value (now it is reported as invalid property value with whole value quited).
Previously it was used only for symantic errors.

CSS error filtering moved into frontend in order to make possible to test the change. The place where filtering happen is not the place where other messages are filtered. It needed in order to not affect warning counter (should filtering be moved entirely into ConsoleModel? I think situation when error counter shows 15 messages but console shoow 3 is confusing).

BUG=140608
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=152130

[SeRya, 2013-06-06 15:41:09]

This includes enables CSS warnings but this part is not supposed to commit (just
for try bots). I'll wait until warnings get enabled.

[SeRya, 2013-06-10 09:13:58]

Reverted testing infrastructure changes.

[apavlov, 2013-06-10 11:13:30]

lgtm

[commit-bot: I haz the power, 2013-06-10 11:13:44]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/serya@chromium.org/16387006/22001

[commit-bot: I haz the power, 2013-06-10 12:55:46]

Change committed as 152130