Revert 210423 "base: Make SequencedWorkerPool issue globally uni..."

Revert 210423 "base: Make SequencedWorkerPool issue globally uni..."

Speculative revert for failing PageCyclerTest.FailProvisionalLoads on
linux_clang.

> base: Make SequencedWorkerPool issue globally unique SequenceTokens.
> 
> SequencedWorkerPool currently issues SequenceTokens out of an internal member counter. This means that two different SequencedWorkerPool instances can issue identical SequenceTokens, which mucks up any attempt to distinguish sequences using only SequenceTokens.
> 
> This change makes the SequenceTokens issued from an StaticAtomicSequenceNumber, which is globally shared amongst all SequencedWorkerPools.
> 
> This change also makes the SequencedWorkerPool included in the nacl_untrusted builds, as it is needed for SequenceChecker and WeakPtr to work correctly. It previously was excluded because it used base/metrics. I've #ifdefed the base/metrics usage out for nacl.
> 
> This issue is a spinoff and pre-requisite of issue 18501008: Make WeakPtr use SequenceChecker instead of ThreadChecker.
> 
> R=akalin,darin
> BUG=165590
> 
> Review URL: https://chromiumcodereview.appspot.com/18650006

TBR=tommycli@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=210433

[scottmg, 2013-07-08 22:31:52]

Committed patchset #1 manually as r210433.

[scottmg, 2013-07-08 22:40:23]

Not too useful, but failure log:

[----------] 4 tests from PageCyclerTest
[ RUN      ] PageCyclerTest.FailProvisionalLoads
Received signal 11 <unknown> 000000000000
 [0x7fb1ee68fd7e] base::debug::StackTrace::StackTrace()
 [0x7fb1ee68f8b7] base::debug::(anonymous namespace)::StackDumpSignalHandler()
 [0x7fb1df7dbcb0] <unknown>
 [0x0000037db713] BrowserList::AddBrowser()
 [0x0000037bf0ef] Browser::Browser()
 [0x000001d9a7bf] BrowserWithTestWindowTest::SetUp()
 [0x000000fc8838] PageCyclerTest::SetUp()
 [0x0000037763b3] testing::internal::HandleSehExceptionsInMethodIfSupported<>()
 [0x00000376d27e] testing::internal::HandleExceptionsInMethodIfSupported<>()
 [0x000003764d73] testing::Test::Run()
 [0x0000037654cb] testing::TestInfo::Run()
 [0x000003765a67] testing::TestCase::Run()
 [0x000003769d95] testing::internal::UnitTestImpl::RunAllTests()
 [0x000003773473] testing::internal::HandleSehExceptionsInMethodIfSupported<>()
 [0x00000376e72e] testing::internal::HandleExceptionsInMethodIfSupported<>()
 [0x000003769a84] testing::UnitTest::Run()
 [0x000004536baf] base::TestSuite::Run()
 [0x0000043e292d] content::UnitTestTestSuite::Run()
 [0x0000041bec64] main
 [0x7fb1dd40876d] __libc_start_main
 [0x0000004fe659] <unknown>
  r8: 00007fff4ce909c0  r9: 00007fff4ce909a0 r10: 00007fff4ce90a40 r11:
0000000000000246
 r12: 000016465163bfb0 r13: 0000000000000000 r14: 0000000006315e30 r15:
0000000006315be8
  di: 0000000000000000  si: 0000164655cbe6b0  bp: 00007fff4ce91070  bx:
0000000006315e68
  dx: 0000000000000001  ax: 0000164655ff6360  cx: 3636363636363636  sp:
00007fff4ce90e70
  ip: 00000000037db713 efl: 0000000000010206 cgf: 0000000000000033 erf:
0000000000000000
 trp: 000000000000000d msk: 0000000000000000 cr2: 0000000000000000