Add a new globals object for PPAPI tracking information.

Add a new globals object for PPAPI tracking information.

[ Reland of 106142: http://codereview.chromium.org/8316008 ]

This adds a specialization on the host and plugin side of the proxy. This
replaces the ad-hoc singleton tracking done by the resource and var trackers
with just being getters on this global object.

Most code can use the single PpapiGlobals class. I also allow code to get the
host and plugin specializations since some code needs access to some specific
features of each side.

In a later pass I'll move the other stuff out of TrackerBase and delete it.

TEST=none
BUG=none
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=106537

[brettw, 2011-10-20 18:08:03]

This is a reland of the previous patch. The previous one broke the shared build.
The original patch is patchset 1, and the new patch is 2.

I just added some build dependencies and added some EXPORT annotations for the
appropriate classes.

TBR since this just fixes the build.

[yzshen1, 2011-10-20 18:18:46]

lgtm