Revert of base: Cleanup: Simplify the declaration of Lock class. (https://codereview.chromium.org/159283003/)

Reason for revert:
This CL seems to cause DevToolsSanityTest.TestReattachAfterCrash to timeout

Original issue's description:
> base: Cleanup: Simplify the declaration of Lock class.
> 
> This is the first step into merging Lock and LockImpl. The later will be
> merged into Lock when things get more clearer.
> 
> BUG=283054
> TEST=base_unittests --gtest_filter=LockTest.*
> R=darin@chromium.org, brettw@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=252864

TBR=brettw@chromium.org,darin@chromium.org,tfarina@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=283054

Review URL: https://codereview.chromium.org/176793002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252869 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252869
Breakpad coverage for chrome_elf start up

Review URL: https://codereview.chromium.org/154653002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252870 0039d316-1c4b-4281-b951-d872f2087c98
Fixed cached ephemeral apps preventing the install of apps

Some code was added to WebstoreStandaloneInstaller to check whether
an extension already exists before proceeding to install. This prevented
any invisible, cached ephemeral apps from being installed permanently.
This fix proceeds with the install if the app is ephemeral.

BUG=312460

Review URL: https://codereview.chromium.org/173483002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252871 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252871