Fix out of bounds array access in memory_details_android.cc.

Fix out of bounds array access in memory_details_android.cc.

AddNonChildChromeProcesses() appeared to be crashing sometimes on Android.
|cmd_line_args_| can be empty in some rare circumstances. One of them is when
GetProcCmdline() is called with a PID which no longer exists. This is possible
in case a render process was killed right after the list of processes was read.

TEST=Go to chrome://memory
BUG=170024
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=177167

[bulach, 2013-01-15 13:22:52]

lgtm

[Philippe, 2013-01-16 14:29:36]

+ jochen since Nico is probably sleeping currently :)

[jochen (gone - plz use gerrit), 2013-01-16 15:50:00]

lgtm

[commit-bot: I haz the power, 2013-01-16 15:52:17]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pliard@chromium.org/11878038/1

[commit-bot: I haz the power, 2013-01-16 17:42:58]

Change committed as 177167