Generate and use LASTCHANGE for blink

Generate and use LASTCHANGE for blink

The main reason for making this change is the fact that when pulling
Chromium and Blink code into Android, we have to make automatic changes
to the repository (for example, for generating *.mk files), and the Blink
commit we have as HEAD doesn't match any public commit in the main 
Blink repo. While via the LASTCHANGE file we could report a publicly 
visible revision.

Also, the way webkit_version.h header is generated now appears to be silly.
First, it doesn't leverage enough existing tools. Second, as it is noted in
webkit_user_agent.gypi, it is broken for incremental builds.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=203387

[mnaganov (inactive), 2013-05-16 18:32:05]

Hi Tony,

What do you think about this idea?

The main reason I'm doing this change is because when pulling Chromium and Blink
code into Android, we have to make automatic changes to the repository (for
example, for generating Android.mk files), and the Blink commit we have as HEAD
doesn't match any public commit in the main Blink repo. While via the LASTCHANGE
file we could report a publicly visible revision.

Also, the way webkit_version.h header is generated now appears to be silly.
First, it doesn't leverage enough existing tools. Second, as it is noted in
webkit_user_agent.gypi, it is broken for incremental builds.

I didn't test the change thoroughly, but if you are OK with the idea, I will
drive this to completion.

[mnaganov (inactive), 2013-05-20 08:38:08]

Tony, ping!

[mnaganov (inactive), 2013-05-21 17:53:21]

I didn't know Tony is on a leave. Michael, can you please take a look at this,
or can you please recommend a more suitable reviewer, if not?

[michaeln, 2013-05-21 20:39:32]

On 2013/05/21 17:53:21, Mikhail Naganov (Chromium) wrote:
> I didn't know Tony is on a leave. Michael, can you please take a look at this,
> or can you please recommend a more suitable reviewer, if not?

looking?

[michaeln, 2013-05-21 21:55:10]

So sorry, but I really don't know what i'm looking at here (either the desired
workflow or py code) and am probably not a good reviewer for this and I'm not
sure who would be?

> On 2013/05/21 17:53:21, Mikhail Naganov (Chromium) wrote:
> > I didn't know Tony is on a leave. Michael, can you please take a look at
this,
> > or can you please recommend a more suitable reviewer, if not?
> 
> looking?

[mnaganov (inactive), 2013-05-22 08:19:26]

Hello, Adam!

Can you please take a look? I know you are not an owner, but I'm sure about your
expertise.

[abarth-chromium, 2013-05-22 15:53:49]

Looks reasonable to me, but I don't know much about this stuff.

[mnaganov (inactive), 2013-05-22 16:10:51]

Darin, can you please give your opinion? It seems hard to find a person who
could give a definite answer.

[mnaganov (inactive), 2013-05-24 08:35:23]

Darin, can you please take a look?

[darin (slow to review), 2013-05-24 21:59:07]

Sorry, I'm not the right guy to review this kind of change.  I defer to
dpranke@.  Conceptually, this makes sense to me.

[mnaganov (inactive), 2013-05-29 12:09:57]

Hi Dirk, can you please take a look?

[Dirk Pranke, 2013-05-29 19:23:22]

On 2013/05/29 12:09:57, Mikhail Naganov (Chromium) wrote:
> Hi Dirk, can you please take a look?

Sorry for the delay. lgtm.

[mnaganov (inactive), 2013-05-29 20:08:39]

On 2013/05/29 19:23:22, Dirk Pranke wrote:
> On 2013/05/29 12:09:57, Mikhail Naganov (Chromium) wrote:
> > Hi Dirk, can you please take a look?
> 
> Sorry for the delay. lgtm.

Awesome, thanks!

Darin, can you please make an owner's review?

[mnaganov (inactive), 2013-05-30 20:11:03]

On 2013/05/29 20:08:39, Mikhail Naganov (Chromium) wrote:
> On 2013/05/29 19:23:22, Dirk Pranke wrote:
> > On 2013/05/29 12:09:57, Mikhail Naganov (Chromium) wrote:
> > > Hi Dirk, can you please take a look?
> > 
> > Sorry for the delay. lgtm.
> 
> Awesome, thanks!
> 
> Darin, can you please make an owner's review?

Darin, ping!

Sorry for bothering, but this CL is in the air for a long time, I would like to
finish with it.

[Dirk Pranke, 2013-05-30 22:17:59]

James, wanna do an owners rubber-stamp for this?

[jamesr, 2013-05-30 22:23:21]

sure! lgtm

[commit-bot: I haz the power, 2013-05-31 08:14:16]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mnaganov@chromium.org/14973005/34001

[mnaganov (inactive), 2013-05-31 08:41:32]

On 2013/05/30 22:23:21, jamesr wrote:
> sure! lgtm

Thanks, James!

[commit-bot: I haz the power, 2013-05-31 08:58:17]

Sorry for I got bad news for ya.
Compile failed with a clobber build on ios_dbg_simulator.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=ios_dbg_si...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-05-31 09:07:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mnaganov@chromium.org/14973005/34001

[commit-bot: I haz the power, 2013-05-31 10:53:40]

Change committed as 203387

[Paweł Hajdan Jr., 2013-06-14 20:43:59]

https://chromiumcodereview.appspot.com/14973005/diff/34001/tools/export_tarba...
File tools/export_tarball/export_tarball.py (right):

https://chromiumcodereview.appspot.com/14973005/diff/34001/tools/export_tarba...
tools/export_tarball/export_tarball.py:143: 'src/third_party/WebKit', '-o',
Note: this broke the script (could be easily detected by running it:

$ tools/export_tarball/export_tarball.py foo
Traceback (most recent call last):
  File "build/util/lastchange.py", line 236, in <module>
    sys.exit(main())
  File "build/util/lastchange.py", line 228, in main
    WriteIfChanged(out_file, contents)
  File "build/util/lastchange.py", line 185, in WriteIfChanged
    open(file_name, 'w').write(contents)
IOError: [Errno 2] No such file or directory: 'src/build/util/LASTCHANGE.blink'
Could not run build/util/lastchange.py to update LASTCHANGE.blink.

I have a CL to fix it, https://codereview.chromium.org/17105005 . This is just
feedback to avoid similar mistakes in the future. Thanks!

[mnaganov (inactive), 2013-06-14 20:52:57]

Sorry for that. I though, I ran the script. Perhaps, got distracted
and skipped it. Thanks for fixing!

On Fri, Jun 14, 2013 at 9:44 PM,  <phajdan.jr@chromium.org> wrote:
>
>
https://chromiumcodereview.appspot.com/14973005/diff/34001/tools/export_tarba...
> File tools/export_tarball/export_tarball.py (right):
>
>
https://chromiumcodereview.appspot.com/14973005/diff/34001/tools/export_tarba...
> tools/export_tarball/export_tarball.py:143: 'src/third_party/WebKit',
> '-o',
> Note: this broke the script (could be easily detected by running it:
>
> $ tools/export_tarball/export_tarball.py foo
> Traceback (most recent call last):
>   File "build/util/lastchange.py", line 236, in <module>
>     sys.exit(main())
>   File "build/util/lastchange.py", line 228, in main
>     WriteIfChanged(out_file, contents)
>   File "build/util/lastchange.py", line 185, in WriteIfChanged
>     open(file_name, 'w').write(contents)
> IOError: [Errno 2] No such file or directory:
> 'src/build/util/LASTCHANGE.blink'
> Could not run build/util/lastchange.py to update LASTCHANGE.blink.
>
> I have a CL to fix it, https://codereview.chromium.org/17105005 . This
> is just feedback to avoid similar mistakes in the future. Thanks!
>
> https://chromiumcodereview.appspot.com/14973005/