Re-implemented the install-build-deps.sh script file, so that on 64 bit...

Re-implemented the install-build-deps.sh script file, so that on 64 bit
systems we build and install proper Debian packages instead of directly
installing files into the filesystem.

This allows the user to cleanly uninstall the packages and it prevents
corruption from us accidentally overwriting files that the system
tries to manage itself.

Also, the script now installs debugging symbols where available. This allows
gdb to step into system libraries. The developer still needs to download the
actual source code with "apt-get source" and point the debugger to it.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=11336

[Markus (顧孟勤), 2009-03-09 04:26:51]

After getting support for 32bit debugging symbols working in an ad hoc fashion
on my machine last week, I figured out how to do this properly. This way, we
don't need to have everybody else go through the same exercise.

I updated the install-build-deps.sh script and in the process pretty much
re-wrote it.

In addition to installing the debugging symbols in the proper location, the
biggest change was the way how we download 32bit libraries.

We used to guess the URL on Ubuntu's server, then downloaded, unpacked and
copied individual files.

Instead, we now use "apt-get" to find and download the 32bit packages for us. We
then unpack and repack them with properly adjusted filenames. This means, the
system actually knows about the 32bit files that we installed. The administrator
can uninstall them with standard system tools. And we get proper errors, when we
try to overwrite existing files.

At this point, we interpret the errors as telling us that we shouldn't install a
particular package because the system already installed the files some other way
(e.g. as part of ia32-libs).

[Evan Martin, 2009-03-09 18:46:46]

I will leave this for dkegel to review, unless he wants otherwise. :)

[Michael Moss, 2009-03-10 16:36:44]

LGTM.