make it possible to set use_system_harfbuzz from outside

make it possible to set use_system_harfbuzz from outside

harfbuzz.gyp overrides any user-specified value for use_system_harfbuzz.
Ideally, it should only override this value for official builds.

BUG=353127
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=263399

[Mostyn Bramley-Moore, 2014-04-10 14:04:00]

@jochen et al: this recent CL made it impossible to set use_system_harfbuzz from
outside: https://codereview.chromium.org/203163003

Shouldn't we be able to set this from gyp command line/GYP_DEFINES environment
variable too, at least for non-official builds?

[jochen (gone - plz use gerrit), 2014-04-10 14:09:56]

i don't have a strong opinion on this. typically, packagers replace the entire
gyp file when using the system implementation (see build/linux/unbundle)

Adding Pawel who might have an opinion on this

[Mostyn Bramley-Moore, 2014-04-10 14:48:36]

On 2014/04/10 14:09:56, jochen wrote:
> i don't have a strong opinion on this. typically, packagers replace the entire
> gyp file when using the system implementation (see build/linux/unbundle)
> 
> Adding Pawel who might have an opinion on this

My problem is that I don't want to use the system harfbuzz in an unofficial
build, but since the local pangoft2 package is recent enough, this forces the
build to use it.

[Paweł Hajdan Jr., 2014-04-10 14:49:01]

LGTM with a comment.

https://codereview.chromium.org/233263002/diff/1/third_party/harfbuzz-ng/harf...
File third_party/harfbuzz-ng/harfbuzz.gyp (right):

https://codereview.chromium.org/233263002/diff/1/third_party/harfbuzz-ng/harf...
third_party/harfbuzz-ng/harfbuzz.gyp:31: 'use_system_harfbuzz': 0,
Consider also changing this one for consistency.

[Mostyn Bramley-Moore, 2014-04-10 15:00:49]

https://codereview.chromium.org/233263002/diff/1/third_party/harfbuzz-ng/harf...
File third_party/harfbuzz-ng/harfbuzz.gyp (right):

https://codereview.chromium.org/233263002/diff/1/third_party/harfbuzz-ng/harf...
third_party/harfbuzz-ng/harfbuzz.gyp:31: 'use_system_harfbuzz': 0,
On 2014/04/10 14:49:01, Paweł Hajdan Jr. wrote:
> Consider also changing this one for consistency.

I figure that you might want buildtype=="Official" to enforce certain settings,
but I don't know if that's something google wants/does.

[jungshik at Google, 2014-04-10 17:41:18]

When setting use_system_harfbuzz to 0 from outside on Ubuntu 13.x, you also need
to disable a linker warning (about duplicate 'symbols') , don't you?

[Mostyn Bramley-Moore, 2014-04-10 21:22:39]

On 2014/04/10 17:41:18, Jungshik Shin wrote:
> When setting use_system_harfbuzz to 0 from outside on Ubuntu 13.x, you also
need
> to disable a linker warning (about duplicate 'symbols') , don't you?

In our forked tree at least, this change is enough to allow us to build without
seeing the following error, when using ubuntu 14.04 and harfbuzz is installed (I
might be wrong about the version of ubuntu- it might have been 13.*):
WebCore::HarfBuzzShaper::setGlyphPositionsForHarfBuzzRun(WebCore::HarfBuzzShaper::HarfBuzzRun*,
hb_buffer_t*): error: undefined reference to 'hb_buffer_get_glyph_positions'
collect2: error: ld returned 1 exit status

I can setup a ubuntu 13.x chroot and build the unforked tree with this patch and
report back, if you like.

[tsniatowski, 2014-04-11 05:53:13]

On 2014/04/10 21:22:39, Mostyn Bramley-Moore wrote:
> On 2014/04/10 17:41:18, Jungshik Shin wrote:
> > When setting use_system_harfbuzz to 0 from outside on Ubuntu 13.x, you also
> need
> > to disable a linker warning (about duplicate 'symbols') , don't you?

I do recall harfbuzz-related linker warnings when building Chrome, but I believe
Mostyn and I were not seeing the duplicated symbols in our build because the
build configuration we use does not link with -lpangoft (use_pango=0).

[Mostyn Bramley-Moore, 2014-04-11 08:46:29]

> I do recall harfbuzz-related linker warnings when building Chrome, but I
believe
> Mostyn and I were not seeing the duplicated symbols in our build because the
> build configuration we use does not link with -lpangoft (use_pango=0).

Ahh right, that explains why I haven't been able to reproduce it.

Any objections to me adding this as-is to the queue?

[jungshik at Google, 2014-04-11 18:39:33]

On 2014/04/11 08:46:29, Mostyn Bramley-Moore wrote:
> > I do recall harfbuzz-related linker warnings when building Chrome, 

bug 353127 is about that  very issue. :-) 

> but I
> believe
> > Mostyn and I were not seeing the duplicated symbols in our build because the
> > build configuration we use does not link with -lpangoft (use_pango=0).
> 
> Ahh right, that explains why I haven't been able to reproduce it.
> 
> Any objections to me adding this as-is to the queue?

Aha.. you're setting use_pango to 0... Ok. let's go with this now (if Jochen is
all right).  LGTM

After that, somehow, we need to take care of  use_pango=1 and
use_system_harfbuzz = 0 on Ubuntu 13.x or later.

[Mostyn Bramley-Moore, 2014-04-11 20:52:37]

The CQ bit was checked by mostynb@opera.com

[commit-bot: I haz the power, 2014-04-11 20:54:57]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mostynb@opera.com/233263002/1

[commit-bot: I haz the power, 2014-04-11 23:23:59]

Change committed as 263399