Revert of Oilpan: Schedule a conservative GC when page navigations are happening frequently

Revert of Oilpan: Schedule a conservative GC when page navigations are happening frequently (patchset #2 id:20001 of https://codereview.chromium.org/1353283002/ )

Reason for revert:
I believe this caused random crashes in the WebGL conformance tests on all platforms as described in http://crbug.com/534524 .


Original issue's description:
> Oilpan: Schedule a conservative GC when page navigations are happening frequently
> 
> A frame retains a lot of memory in the V8 side. For example, one v8::Context retained
> by the frame has >200 KB. V8's GC cannot collect the memory until Oilpan's GC collects
> the frame. So this CL forces a conservative GC if no Oilpan's GC has been observed in
> the past 5 frame navigations.
> 
> This CL improves the performance of iframe-append-child as follows:
> 
> ToT without Oilpan: 177 runs/sec
> ToT with Oilpan: 142 runs/sec
> ToT + this CL with Oilpan: 168 runs/sec
> 
> This CL also reduces V8's peak memory usage as follows:
> 
> ToT without Oilpan: 34 MB
> ToT with Oilpan: 110 MB
> ToT + this CL with Oilpan: 50 MB
> 
> (Note: iframe-append-child uses little memory in the Blink side.
> allocatedObjectSize + PartitionAlloc <= 4 MB.)
> 
> BUG=
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=202568

TBR=oilpan-reviews@chromium.org,keishi@chromium.org,sigbjornf@opera.se,sigbjornf@opera.com,haraken@chromium.org
BUG=534524
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=202613

[Ken Russell (switch to Gerrit), 2015-09-21 22:17:55]

Created Revert of Oilpan: Schedule a conservative GC when page navigations are
happening frequently

[Ken Russell (switch to Gerrit), 2015-09-21 22:18:27]

FYI.

[Ken Russell (switch to Gerrit), 2015-09-21 22:18:31]

The CQ bit was checked by kbr@chromium.org

[commit-bot: I haz the power, 2015-09-21 22:19:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1351943004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1351943004/1

[Ken Russell (switch to Gerrit), 2015-09-21 23:17:17]

On 2015/09/21 22:19:13, commit-bot: I haz the power wrote:
> CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/1351943004/1
> View timeline at
>  https://chromium-cq-status.appspot.com/patch-timeline/1351943004/1

Updated http://crbug.com/487092 regarding flaky
virtual/threaded/animations/multiple-same-animations-asan-crash.html crash in
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...
.

[commit-bot: I haz the power, 2015-09-21 23:54:49]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=202613

[haraken, 2015-09-21 23:58:25]

On 2015/09/21 23:54:49, commit-bot: I haz the power wrote:
> Committed patchset #1 (id:1) as
> https://src.chromium.org/viewvc/blink?view=rev&revision=202613

Thanks for the revert, LGTM.

(This will be fixed in https://codereview.chromium.org/1358813002/.)