Reland of "Remove void** from disk_cache interface."

Reland of "Remove void** from disk_cache interface."

Enumeration and iteration were passing around void**. With this CL, we
instead use an Iterator object.

TBR=clamy@chromium.org,jkarlin@chromium.org,jsbell@chromium.org
BUG=413644
Committed: https://crrev.com/edbfba945a76d97383122a01529abfe3ce63d34d
Cr-Commit-Position: refs/heads/master@{#295870}

[gavinp, 2014-09-19 16:04:12]

Patchset #1 (id:1) has been deleted

[gavinp, 2014-09-19 16:45:55]

https://codereview.chromium.org/583283002/diff/40001/net/disk_cache/blockfile...
File net/disk_cache/blockfile/backend_impl.cc (right):

https://codereview.chromium.org/583283002/diff/40001/net/disk_cache/blockfile...
net/disk_cache/blockfile/backend_impl.cc:1261:
background_queue_->EndEnumeration(data_);
Unfortunately, this still leaks if the iterator is not deleted before the
backend. I'm making a followup CL to fix this.

[gavinp, 2014-09-19 18:12:17]

On 2014/09/19 16:45:55, gavinp wrote:
>
https://codereview.chromium.org/583283002/diff/40001/net/disk_cache/blockfile...
> File net/disk_cache/blockfile/backend_impl.cc (right):
> 
>
https://codereview.chromium.org/583283002/diff/40001/net/disk_cache/blockfile...
> net/disk_cache/blockfile/backend_impl.cc:1261:
> background_queue_->EndEnumeration(data_);
> Unfortunately, this still leaks if the iterator is not deleted before the
> backend. I'm making a followup CL to fix this.

See https://codereview.chromium.org/583293002/ for the fix to the memory leak.

[rvargas (doing something else), 2014-09-20 00:47:59]

rvargas@chromium.org changed reviewers:
+ rvargas@chromium.org

[rvargas (doing something else), 2014-09-20 00:47:59]

lgtm

[gavinp, 2014-09-20 04:00:38]

The CQ bit was checked by gavinp@chromium.org

[commit-bot: I haz the power, 2014-09-20 04:01:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/583283002/40001

[commit-bot: I haz the power, 2014-09-20 13:20:51]

Committed patchset #2 (id:40001) as 1e2fe47b88506c2754b9820fc4a0c15c5388c3fb

[commit-bot: I haz the power, 2014-09-20 13:21:29]

Patchset 2 (id:??) landed as
https://crrev.com/edbfba945a76d97383122a01529abfe3ce63d34d
Cr-Commit-Position: refs/heads/master@{#295870}

[dcheng, 2014-09-20 19:46:34]

A revert of this CL (patchset #2 id:40001) has been created in
https://codereview.chromium.org/592503002/ by dcheng@chromium.org.

The reason for reverting is: Suspected for causing accessibility tests to
flake..

[dcheng, 2014-09-20 19:50:58]

On 2014/09/20 at 19:46:34, dcheng (OOO) wrote:
> A revert of this CL (patchset #2 id:40001) has been created in
https://codereview.chromium.org/592503002/ by dcheng@chromium.org.
> 
> The reason for reverting is: Suspected for causing accessibility tests to
flake..

Windows waterfall failure @
https://build.chromium.org/p/chromium.win/builders/Win%207%20Tests%20x64%20%2...

Output:
DumpAccessibilityTreeTest.AccessibilityAriaListBoxAriaSelected (run #1):
[ RUN      ] DumpAccessibilityTreeTest.AccessibilityAriaListBoxAriaSelected
Testing:
E:\b\build\slave\Win_7_Tests_x64__1_\build\src\content\test\data\accessibility\aria-listbox-aria-selected.html
Skipping this test on this platform.
Backtrace:
	std::_Tree\u003Cstd::_Tset_traits\u003Cscoped_refptr\u003Cdisk_cache::BackgroundIO>,std::less\u003Cscoped_refptr\u003Cdisk_cache::BackgroundIO>
>,std::allocator\u003Cscoped_refptr\u003Cdisk_cache::BackgroundIO> >,0> >::erase
[0x00000001401CCD0F+31]

Mac trybot failure @
https://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel...

Output:
DumpAccessibilityTreeTest.AccessibilityAriaAutocomplete (run #2):
[ RUN      ] DumpAccessibilityTreeTest.AccessibilityAriaAutocomplete
[7061:27651:0920/073510:32084495359197:FATAL:weak_ptr.cc(26)] Check failed:
sequence_checker_.CalledOnValidSequencedThread(). WeakPtrs must be checked on
the same sequenced thread.

[dcheng, 2014-09-20 20:16:28]

On 2014/09/20 at 19:50:58, dcheng (OOO) wrote:
> On 2014/09/20 at 19:46:34, dcheng (OOO) wrote:
> > A revert of this CL (patchset #2 id:40001) has been created in
https://codereview.chromium.org/592503002/ by dcheng@chromium.org.
> > 
> > The reason for reverting is: Suspected for causing accessibility tests to
flake..
> 
> Windows waterfall failure @
https://build.chromium.org/p/chromium.win/builders/Win%207%20Tests%20x64%20%2...
> 
> Output:
> DumpAccessibilityTreeTest.AccessibilityAriaListBoxAriaSelected (run #1):
> [ RUN      ] DumpAccessibilityTreeTest.AccessibilityAriaListBoxAriaSelected
> Testing:
E:\b\build\slave\Win_7_Tests_x64__1_\build\src\content\test\data\accessibility\aria-listbox-aria-selected.html
> Skipping this test on this platform.
> Backtrace:
>
	std::_Tree\u003Cstd::_Tset_traits\u003Cscoped_refptr\u003Cdisk_cache::BackgroundIO>,std::less\u003Cscoped_refptr\u003Cdisk_cache::BackgroundIO>
>,std::allocator\u003Cscoped_refptr\u003Cdisk_cache::BackgroundIO> >,0> >::erase
[0x00000001401CCD0F+31]
> 
> Mac trybot failure @
https://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel...
> 
> Output:
> DumpAccessibilityTreeTest.AccessibilityAriaAutocomplete (run #2):
> [ RUN      ] DumpAccessibilityTreeTest.AccessibilityAriaAutocomplete
> [7061:27651:0920/073510:32084495359197:FATAL:weak_ptr.cc(26)] Check failed:
sequence_checker_.CalledOnValidSequencedThread(). WeakPtrs must be checked on
the same sequenced thread.

Another failure stack from
http://build.chromium.org/p/chromium.win/builders/Win7%20Tests%20(1)/builds/3...:

[ RUN      ]
InlineLoginUISafeIframeBrowserTest.NavigationToOtherChromeURLDisallowed
[1328:3576:0920/080805:WARNING:chrome_browser_main_win.cc(312)] Command line too
long for RegisterApplicationRestart
[1328:2832:0920/080805:WARNING:embedded_test_server.cc(242)] Request not
handled. Returning 404:
/ServiceLogin?skipvpage=true&sarp=1&rm=hide&service=chromiumsync&continue=chrome-extension%3A%2F%2Fmfffpogegjflfpflabcdkioaeobkgjik%2Fsuccess.html%3Fsource%3D0&hl=en-US
Backtrace:
	std::_Tree\u003Cstd::_Tset_traits\u003Cscoped_refptr\u003Ccontent::TraceMessageFilter>,std::less\u003Cscoped_refptr\u003Ccontent::TraceMessageFilter>
>,std::allocator\u003Cscoped_refptr\u003Ccontent::TraceMessageFilter> >,0>
>::_Eqrange [0x01BD851D+13]
	disk_cache::InFlightIO::InvokeCallback [0x01C1F09D+93]
	disk_cache::BackgroundIO::OnIOSignalled [0x01C1F1D1+17]
	base::MessageLoop::RunTask [0x01A4FAC8+568]
	base::MessageLoop::DoWork [0x01A4F3A6+998]
	base::MessagePumpForIO::DoRunLoop [0x01A7E2D5+549]
	base::MessagePumpWin::Run [0x01A7E8ED+61]
	base::MessageLoop::RunHandler [0x01A4F880+48]
	base::MessageLoop::Run [0x01A4F836+22]
	base::Thread::Run [0x01A6371B+11]
	content::BrowserThreadImpl::IOThreadRun [0x0243827F+31]
	content::BrowserThreadImpl::Run [0x024388B1+177]
	base::Thread::ThreadMain [0x01A63B10+384]
	base::`anonymous namespace'::ThreadFunc [0x01A60761+113]
	BaseThreadInitThunk [0x768033AA+18]
	RtlInitializeExceptionChain [0x77A49EF2+99]
	RtlInitializeExceptionChain [0x77A49EC5+54]

[gavinp, 2014-09-22 16:38:57]

dcheck,

Good catch. The problem was actually already known, and fixed in a downstream CL
https://codereview.chromium.org/583293002/ , which should have been combined
with this to land.

I've now put the two together, and made the combined CL
https://codereview.chromium.org/588243002/ , which fixes the bug you found that
really shouldn't have been dealt with separately.