don't clobber PKG_CONFIG_PATH, allow cross-compilation without a sysroot

don't clobber PKG_CONFIG_PATH, allow cross-compilation without a sysroot

This change makes it possible to cross-compile chromium without a proper
sysroot for the target, by making it possible to provide a specific
PKG_CONFIG_PATH directory.

BUG=

[mostynb, 2013-02-20 21:19:55]

Hi, this is my first chromium patch so I'm using this as a trial run- are you
able to review this?

About the patch itself: this allows us to cross compile chromium without a full
sysroot.  By setting PKG_CONFIG_PATH manually the wrapper script assumes that
you know what you're doing and doesn't modify the value.

[piman, 2013-02-21 00:52:01]

On 2013/02/20 21:19:55, mostynb wrote:
> Hi, this is my first chromium patch so I'm using this as a trial run- are you
> able to review this?
> 
> About the patch itself: this allows us to cross compile chromium without a
full
> sysroot.  By setting PKG_CONFIG_PATH manually the wrapper script assumes that
> you know what you're doing and doesn't modify the value.

LGTM, this looks fairly reasonable. One question about the patch: the
pkg-config-wrapper script is only used when the sysroot gyp define is set. Does
that mean you're using this by setting a sysroot, but expecting the pkg-config
files to be somewhere unrelated?

NB: I need to double-check with our legal people about the status of Opera wrt
our Contributor License Agreement. Once that is cleared, I'm happy to land this.

[piman, 2013-02-21 00:53:17]

On 2013/02/21 00:52:01, piman wrote:
> On 2013/02/20 21:19:55, mostynb wrote:
> > Hi, this is my first chromium patch so I'm using this as a trial run- are
you
> > able to review this?
> > 
> > About the patch itself: this allows us to cross compile chromium without a
> full
> > sysroot.  By setting PKG_CONFIG_PATH manually the wrapper script assumes
that
> > you know what you're doing and doesn't modify the value.
> 
> LGTM, this looks fairly reasonable. One question about the patch: the
> pkg-config-wrapper script is only used when the sysroot gyp define is set.
Does
> that mean you're using this by setting a sysroot, but expecting the pkg-config
> files to be somewhere unrelated?
> 
> NB: I need to double-check with our legal people about the status of Opera wrt
> our Contributor License Agreement. Once that is cleared, I'm happy to land
this.

Oh, and one more thing, is it possible to upload this patch from your @opera.com
e-mail address (to match the AUTHORS file)?

[piman, 2013-02-21 01:51:04]

On 2013/02/21 00:52:01, piman wrote:
> On 2013/02/20 21:19:55, mostynb wrote:
> > Hi, this is my first chromium patch so I'm using this as a trial run- are
you
> > able to review this?
> > 
> > About the patch itself: this allows us to cross compile chromium without a
> full
> > sysroot.  By setting PKG_CONFIG_PATH manually the wrapper script assumes
that
> > you know what you're doing and doesn't modify the value.
> 
> LGTM, this looks fairly reasonable. One question about the patch: the
> pkg-config-wrapper script is only used when the sysroot gyp define is set.
Does
> that mean you're using this by setting a sysroot, but expecting the pkg-config
> files to be somewhere unrelated?
> 
> NB: I need to double-check with our legal people about the status of Opera wrt
> our Contributor License Agreement. Once that is cleared, I'm happy to land
this.

I checked the latter and it's fine as long as you upload from an @opera.com
address, then I can land it. Thanks!

[Mostyn Bramley-Moore, 2013-02-21 09:08:00]

On 2013/02/21 01:51:04, piman wrote:
> On 2013/02/21 00:52:01, piman wrote:
> > On 2013/02/20 21:19:55, mostynb wrote:
> > > Hi, this is my first chromium patch so I'm using this as a trial run- are
> you
> > > able to review this?
> > > 
> > > About the patch itself: this allows us to cross compile chromium without a
> > full
> > > sysroot.  By setting PKG_CONFIG_PATH manually the wrapper script assumes
> that
> > > you know what you're doing and doesn't modify the value.
> > 
> > LGTM, this looks fairly reasonable. One question about the patch: the
> > pkg-config-wrapper script is only used when the sysroot gyp define is set.
> Does
> > that mean you're using this by setting a sysroot, but expecting the
pkg-config
> > files to be somewhere unrelated?

Aha- I was not setting a sysroot but it seems that a default (which does not
exist) is being provided for linux (non-chromeos) arm targets in
build/common.gypi.  I also notice that sysroot is always enabled for mipsel,
rather than providing a default.  Should I create new issues for these, or add
additional patches here?

However I think this patch is still useful for targets where the pkg-config
files are not in the directories pkg-config-wrapper expects (I have at least one
such system).

> > NB: I need to double-check with our legal people about the status of Opera
wrt
> > our Contributor License Agreement. Once that is cleared, I'm happy to land
> this.
> 
> I checked the latter and it's fine as long as you upload from an @opera.com
> address, then I can land it. Thanks!

I have now linked my @opera.com email address with this account- is this
sufficient, or do I still need to re-upload?

Thanks :)

[Mostyn Bramley-Moore, 2013-02-21 09:16:19]

> However I think this patch is still useful for targets where the pkg-config
> files are not in the directories pkg-config-wrapper expects (I have at least
one
> such system).

(I meant to say "for targets where you have a full sysroot, but the pkg-config
files are not in the directories pkg-config-wrapper expects"...)

[Mostyn Bramley-Moore, 2013-02-21 20:39:43]

Re-uploaded using my @opera account here (with a better commit message):
https://codereview.chromium.org/12320047/