Remove CachingValueStore in favor of an async ValueStoreFrontend.

Remove CachingValueStore in favor of an async ValueStoreFrontend.

After actually seeing the use cases for the value store in extension code, I
realized that an async version would be more appropriate. This one will use
less memory as well, since we won't need to keep the cache in memory.

BUG=123366
TEST=no


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=141514

[Matt Perry, 2012-06-08 20:35:40]

Sorry for the flipflopping. Turns out CachingValueStore was a bad idea.

I'll have another CL coming shortly that makes use of this new thing.

[not at google - send to devlin, 2012-06-10 11:06:08]

lgtm

http://codereview.chromium.org/10539073/diff/1/chrome/browser/value_store/val...
File chrome/browser/value_store/value_store_frontend.cc (right):

http://codereview.chromium.org/10539073/diff/1/chrome/browser/value_store/val...
chrome/browser/value_store/value_store_frontend.cc:20: void Get(const
std::string& key, ValueStoreFrontend::ReadCallback callback) {
ditto, const& ?

http://codereview.chromium.org/10539073/diff/1/chrome/browser/value_store/val...
File chrome/browser/value_store/value_store_frontend.h (right):

http://codereview.chromium.org/10539073/diff/1/chrome/browser/value_store/val...
chrome/browser/value_store/value_store_frontend.h:31: void Get(const
std::string& key, ReadCallback callback);
I think callbacks can be passed as const&

[Matt Perry, 2012-06-11 20:09:15]

http://codereview.chromium.org/10539073/diff/1/chrome/browser/value_store/val...
File chrome/browser/value_store/value_store_frontend.h (right):

http://codereview.chromium.org/10539073/diff/1/chrome/browser/value_store/val...
chrome/browser/value_store/value_store_frontend.h:31: void Get(const
std::string& key, ReadCallback callback);
On 2012/06/10 11:06:08, kalman wrote:
> I think callbacks can be passed as const&

Done.

[commit-bot: I haz the power, 2012-06-11 20:09:27]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mpcomplete@chromium.org/10539073/8001

[commit-bot: I haz the power, 2012-06-11 21:53:11]

Change committed as 141514