Reland: Add --no-history option to fetch and gclient for shallow clones.

Reland: Add --no-history option to fetch and gclient for shallow clones.

Original CL: https://codereview.chromium.org/440263002/

Many people* have complained on chromium-dev about the long times
required to perform a full fetch over a DSL. This seems to be mostly
due to the huge size of chromium's history (~9 GB). On the other side,
not everybody is interested in downloading the full git history of
the projects. The size of git packs required to fetch a working HEAD
is one order of magnitude smaller (1.5 GB).
This change makes it possible to perform a shallow fetch (in a way
which is consistent with DEPS, leveraging git templates on clone),
reducing fetch times by 80% for those not interested in the history.

* See:
[chromium-dev] "fetch chromium" keeps hanging/getting stuck on Windows 7
[chromium-dev] Initial checkout with git taking long
[chromium-dev] Trying to get latest source code fails when fetching
[chromium-dev] Gclient sync takes too long

BUG=228996
TBR=iannucci@chromium.org,szager@chromium.org,wtc@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=287793

[Primiano Tucci (use gerrit), 2014-08-06 17:00:36]

Relanding the --no-history CL (original: crrev.com/437903002)
TBR-ing since this is a one line diff from the original which was already
LGTem'd

Diff: gclient_scm.py
     template_dir = None
-    if options.no_history:
+    if options.ensure_value('no_history', False):

Essentially, turns out that the _clone method is called also by CMDRevert
(sigh), and the latter doesn't have a --no-history in its options, causing the
failure reported in crrev.com/437903002

[Primiano Tucci (use gerrit), 2014-08-06 17:02:07]

The CQ bit was checked by primiano@chromium.org

[commit-bot: I haz the power, 2014-08-06 17:02:19]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/primiano@chromium.org/440273002/1

[commit-bot: I haz the power, 2014-08-06 17:04:11]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-08-06 17:04:12]

Presubmit check for 440273002-1 failed and returned exit status 1.

Running presubmit commit checks ...
Checking out rietveld...
Running save-description-on-failure.sh
Running push-basic.sh
Running upstream.sh
Running submit-from-new-dir.sh
Running abandon.sh
Running submodule-merge-test.sh
Running upload-local-tracking-branch.sh
Running hooks.sh
Running post-dcommit-hook-test.sh
Running upload-stale.sh
Running patch.sh
Running basic.sh

** Presubmit Messages **
--tbr was specified, skipping OWNERS check

** Presubmit ERRORS **
tests/gclient_scm_test.py (6.79s) failed
............................................EEEEEEEEEE.
======================================================================
ERROR: testUpdateClone (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 1431, in testUpdateClone
    scm.update(options, (), file_list)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
389, in update
    self._Clone(revision, url, options)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
830, in _Clone
    if options.ensure_value('no_history', False):
AttributeError: 'OptionsObject' object has no attribute 'ensure_value'

======================================================================
ERROR: testUpdateClone (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 914, in tearDown
    StdoutCheck.tearDown(self)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/testing_support/super_mox.py",
line 102, in tearDown
    self.assertEquals('', sys.stdout.getvalue())
AssertionError: '' != '[0:00:06] \n'

======================================================================
ERROR: testUpdateCloneOnBranch (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 1495, in testUpdateCloneOnBranch
    scm.update(options, (), file_list)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
389, in update
    self._Clone(revision, url, options)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
830, in _Clone
    if options.ensure_value('no_history', False):
AttributeError: 'OptionsObject' object has no attribute 'ensure_value'

======================================================================
ERROR: testUpdateCloneOnBranch (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 914, in tearDown
    StdoutCheck.tearDown(self)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/testing_support/super_mox.py",
line 102, in tearDown
    self.assertEquals('', sys.stdout.getvalue())
AssertionError: '' != '[0:00:06] \n'

======================================================================
ERROR: testUpdateCloneOnBranchHead (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 1557, in testUpdateCloneOnBranchHead
    scm.update(options, (), file_list)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
389, in update
    self._Clone(revision, url, options)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
830, in _Clone
    if options.ensure_value('no_history', False):
AttributeError: 'OptionsObject' object has no attribute 'ensure_value'

======================================================================
ERROR: testUpdateCloneOnBranchHead (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 914, in tearDown
    StdoutCheck.tearDown(self)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/testing_support/super_mox.py",
line 102, in tearDown
    self.assertEquals('', sys.stdout.getvalue())
AssertionError: '' != '[0:00:06] \n'

======================================================================
ERROR: testUpdateCloneOnCommit (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 1463, in testUpdateCloneOnCommit
    scm.update(options, (), file_list)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
389, in update
    self._Clone(revision, url, options)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
830, in _Clone
    if options.ensure_value('no_history', False):
AttributeError: 'OptionsObject' object has no attribute 'ensure_value'

======================================================================
ERROR: testUpdateCloneOnCommit (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 914, in tearDown
    StdoutCheck.tearDown(self)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/testing_support/super_mox.py",
line 102, in tearDown
    self.assertEquals('', sys.stdout.getvalue())
AssertionError: '' != '[0:00:06] \n'

======================================================================
ERROR: testUpdateCloneOnDetachedBranch (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 1525, in
testUpdateCloneOnDetachedBranch
    scm.update(options, (), file_list)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
389, in update
    self._Clone(revision, url, options)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/gclient_scm.py", line
830, in _Clone
    if options.ensure_value('no_history', False):
AttributeError: 'OptionsObject' object has no attribute 'ensure_value'

======================================================================
ERROR: testUpdateCloneOnDetachedBranch (__main__.UnmanagedGitWrapperTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/gclient_scm_test.py", line 914, in tearDown
    StdoutCheck.tearDown(self)
  File
"/b/infra_internal/commit_queue/workdir/tools/depot_tools/testing_support/super_mox.py",
line 102, in tearDown
    self.assertEquals('', sys.stdout.getvalue())
AssertionError: '' != '[0:00:06] \n'

----------------------------------------------------------------------
Ran 50 tests in 6.497s

FAILED (errors=10)


Presubmit checks took 101.5s to calculate.

[Primiano Tucci (use gerrit), 2014-08-06 17:16:14]

The CQ bit was checked by primiano@chromium.org

[commit-bot: I haz the power, 2014-08-06 17:16:33]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/primiano@chromium.org/440273002/20001

[commit-bot: I haz the power, 2014-08-06 17:18:20]

Change committed as 287793