Replace blink::WebDiscardableMemory with base::DiscardableMemory.

Replace blink::WebDiscardableMemory with base::DiscardableMemory.

* Inline WebDiscardableMemoryImpl into its only user, PurgeableVector, which is
  allowed to see base by virtue of being in platform.
* Augment base::TestDiscardableMemoryAllocator's implementation with the same
  checks as Blink's.
* Observing that the actual implementation never returns nullptr, remove logic
  that handles that (as other clients of base::DiscardableMemoryAllocator don't).
* Supply a base::TestDiscardableMemoryAllocator in blink_platform_unittests.
* Modify PurgeableVectorTest to vary only whether PurgeableVector requests
  discardable memory (PurgeableOption), since Blink's real platform (Chromium)
  does support it. Change all tests which don't vary in this way to be not
  parameterized.

Committed: https://crrev.com/36fc372117d5c40162dc014aaba4bbb7e3d5779a
Cr-Commit-Position: refs/heads/master@{#381378}

[jbroman, 2016-03-14 16:01:35]

Description was changed from

==========
Replace blink::WebDiscardableMemory with base::DiscardableMemory.

Also augment base::TestDiscardableMemoryAllocator's implementation with the
same checks as Blink's; what's good for the goose is good for the gander.
==========

to

==========
Replace blink::WebDiscardableMemory with base::DiscardableMemory.

* Inline WebDiscardableMemoryImpl into its only user, PurgeableVector, which is
  allowed to see base by virtue of being in platform.
* Augment base::TestDiscardableMemoryAllocator's implementation with the same
  checks as Blink's.
* Observing that the actual implementation never returns nullptr, remove logic
  that handles that (as other clients of base::DiscardableMemoryAllocator
don't).
* Supply a base::TestDiscardableMemoryAllocator in blink_platform_unittests.
* Modify PurgeableVectorTest to vary only whether PurgeableVector requests
  discardable memory (PurgeableOption), since Blink's real platform (Chromium)
  does support it. Change all tests which don't vary in this way to be not
  parameterized.
==========

[jbroman, 2016-03-14 17:26:52]

jbroman@chromium.org changed reviewers:
+ danakj@chromium.org, esprehn@chromium.org

[jbroman, 2016-03-14 17:26:52]

esprehn for content/child/ and third_party/WebKit/, danakj for base/

This seems a straightforward simplification to reduce the indirection through
public/platform/, especially since it has only one client, and that client is in
Source/platform/ already.

[danakj, 2016-03-14 18:03:34]

base LGTM

[jbroman, 2016-03-15 20:13:12]

ping esprehn?

[esprehn, 2016-03-15 20:43:26]

lgtm, please be patient during perf. :)

https://codereview.chromium.org/1787973002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/PurgeableVector.cpp (right):

https://codereview.chromium.org/1787973002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/PurgeableVector.cpp:92:
std::string(utf8DumpName.data(), utf8DumpName.length()), m_discardable.get());
.asStringPiece().as_string() would work too?

[jbroman, 2016-03-15 23:25:18]

The CQ bit was checked by jbroman@chromium.org

[jbroman, 2016-03-15 23:25:18]

The patchset sent to the CQ was uploaded after l-g-t-m from danakj@chromium.org,
esprehn@chromium.org
Link to the patchset: https://codereview.chromium.org/1787973002/#ps100001
(title: "use StringPiece::as_string")

[commit-bot: I haz the power, 2016-03-15 23:25:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1787973002/100001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1787973002/100001

[jbroman, 2016-03-15 23:27:03]

On 2016/03/15 at 20:43:26, esprehn wrote:
> lgtm, please be patient during perf. :)

Didn't mean to be impatient; was hoping to catch you _before_ you got super
busy. :)

https://codereview.chromium.org/1787973002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/PurgeableVector.cpp (right):

https://codereview.chromium.org/1787973002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/PurgeableVector.cpp:92:
std::string(utf8DumpName.data(), utf8DumpName.length()), m_discardable.get());
On 2016/03/15 at 20:43:26, esprehn wrote:
> .asStringPiece().as_string() would work too?

Sure would. It sounds like you prefer .asStringPiece().as_string(), so I'll do
that.

[jbroman, 2016-03-15 23:27:10]

The CQ bit was unchecked by jbroman@chromium.org

[jbroman, 2016-03-15 23:31:27]

The CQ bit was checked by jbroman@chromium.org

[commit-bot: I haz the power, 2016-03-15 23:32:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1787973002/100001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1787973002/100001

[commit-bot: I haz the power, 2016-03-16 01:52:17]

Committed patchset #6 (id:100001)

[commit-bot: I haz the power, 2016-03-16 01:53:53]

Description was changed from

==========
Replace blink::WebDiscardableMemory with base::DiscardableMemory.

* Inline WebDiscardableMemoryImpl into its only user, PurgeableVector, which is
  allowed to see base by virtue of being in platform.
* Augment base::TestDiscardableMemoryAllocator's implementation with the same
  checks as Blink's.
* Observing that the actual implementation never returns nullptr, remove logic
  that handles that (as other clients of base::DiscardableMemoryAllocator
don't).
* Supply a base::TestDiscardableMemoryAllocator in blink_platform_unittests.
* Modify PurgeableVectorTest to vary only whether PurgeableVector requests
  discardable memory (PurgeableOption), since Blink's real platform (Chromium)
  does support it. Change all tests which don't vary in this way to be not
  parameterized.
==========

to

==========
Replace blink::WebDiscardableMemory with base::DiscardableMemory.

* Inline WebDiscardableMemoryImpl into its only user, PurgeableVector, which is
  allowed to see base by virtue of being in platform.
* Augment base::TestDiscardableMemoryAllocator's implementation with the same
  checks as Blink's.
* Observing that the actual implementation never returns nullptr, remove logic
  that handles that (as other clients of base::DiscardableMemoryAllocator
don't).
* Supply a base::TestDiscardableMemoryAllocator in blink_platform_unittests.
* Modify PurgeableVectorTest to vary only whether PurgeableVector requests
  discardable memory (PurgeableOption), since Blink's real platform (Chromium)
  does support it. Change all tests which don't vary in this way to be not
  parameterized.

Committed: https://crrev.com/36fc372117d5c40162dc014aaba4bbb7e3d5779a
Cr-Commit-Position: refs/heads/master@{#381378}
==========

[commit-bot: I haz the power, 2016-03-16 01:53:54]

Patchset 6 (id:??) landed as
https://crrev.com/36fc372117d5c40162dc014aaba4bbb7e3d5779a
Cr-Commit-Position: refs/heads/master@{#381378}