Cherry-pick: [Android WebView] Change tile size to 384

Cherry-pick of Chromium

BUG: 11446261

Original description:

512x512 tiles uses exactly 1MB in memory. However the allocator
on certain devices allocates 1.25MB instead (due to performance
heuristics), so 20% of allocated tile memory is wasted in this

Determined experimentally that 384 tiles do not have any overhead, so
update tile size to 384.

Also reduce the number of resources per webview from 200 to 150 to
overcome potential file handle limit problems, and add a command line
switch to control this value.

Change-Id: I76f333d9ffac4295150155f9d029de44a54e9cd0
3 files changed