Forward declaration for Isolate / Platform in libplatform.h.

Forward declaration for Isolate / Platform in libplatform.h.

Reduces dependencies on #include files, making it easier for other
build systems to include this library.

BUG=

Committed: https://chromium.googlesource.com/v8/v8/+/6dafd81ae2a1848e276dd38aa51bb0acd2e7a19a

[bulach, 2014-11-18 19:24:10]

bulach@chromium.org changed reviewers:
+ jochen@chromium.org

[bulach, 2014-11-18 19:24:10]

hello again :) this will make my life easier on "the other side", please let me
know your thoughts.

[jochen (gone - plz use gerrit), 2014-11-18 19:27:59]

lgtm.

[jochen (gone - plz use gerrit), 2014-11-18 19:28:13]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-11-18 19:28:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/740493002/1

[commit-bot: I haz the power, 2014-11-18 19:37:02]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-11-18 19:37:03]

Try jobs failed on following builders:
  v8_mac_rel on tryserver.v8
(http://build.chromium.org/p/tryserver.v8/builders/v8_mac_rel/builds/1372)

[bulach, 2014-11-18 19:37:52]

On 2014/11/18 19:37:03, I haz the power (commit-bot) wrote:
> Try jobs failed on following builders:
>   v8_mac_rel on tryserver.v8
> (http://build.chromium.org/p/tryserver.v8/builders/v8_mac_rel/builds/1372)

ops. sorry... on it, uploading new patchset shortly..

[bulach, 2014-11-18 19:48:37]

another look please?

[jochen (gone - plz use gerrit), 2014-11-18 20:00:49]

still lgtm

[jochen (gone - plz use gerrit), 2014-11-18 20:00:51]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-11-18 20:01:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/740493002/20001

[commit-bot: I haz the power, 2014-11-18 20:29:31]

Committed patchset #2 (id:20001)