IndexedDB: Add performance test calling continue(key)

IndexedDB: Add performance test calling continue(key)

Upcoming patch http://wkbug.com/109972 changes this from a linear walk to a seek (log N, presumably)

NOTRY=true
BUG=175172
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=188754

[jsbell, 2013-03-15 19:44:12]

dgrogan@, ericu@ - please take a look?

Pre-webkit patch I see times around 100ms/300ms. After the patch it's down to
9ms/9ms

(The test control numbers were tweaked to make sure those numbers were
reasonable before/after the test)

[dgrogan, 2013-03-16 00:49:51]

lgtm

https://codereview.chromium.org/12780007/diff/1/chrome/test/data/indexeddb/pe...
File chrome/test/data/indexeddb/perf_test.js (right):

https://codereview.chromium.org/12780007/diff/1/chrome/test/data/indexeddb/pe...
chrome/test/data/indexeddb/perf_test.js:635: console.log("created: " +
testName);
Unintentional?

https://codereview.chromium.org/12780007/diff/1/chrome/test/data/indexeddb/pe...
chrome/test/data/indexeddb/perf_test.js:654: var source = os;
I'd say get rid of the os variable.

https://codereview.chromium.org/12780007/diff/1/chrome/test/data/indexeddb/pe...
chrome/test/data/indexeddb/perf_test.js:664: var request = useIndexForReads ?
source.openKeyCursor()
Why not always use a CursorWithValue?

[jsbell, 2013-03-17 06:13:06]

>
https://codereview.chromium.org/12780007/diff/1/chrome/test/data/indexeddb/pe...
> chrome/test/data/indexeddb/perf_test.js:635: console.log("created: " +
> testName);
> Unintentional?
> 

Oops, thanks. 

>
https://codereview.chromium.org/12780007/diff/1/chrome/test/data/indexeddb/pe...
> chrome/test/data/indexeddb/perf_test.js:654: var source = os;
> I'd say get rid of the os variable.
> 

Will do. 

>
https://codereview.chromium.org/12780007/diff/1/chrome/test/data/indexeddb/pe...
> chrome/test/data/indexeddb/perf_test.js:664: var request = useIndexForReads ?
> source.openKeyCursor()
> Why not always use a CursorWithValue?

I wanted to contrast the times with and without value lookup/deserislization.

[commit-bot: I haz the power, 2013-03-18 16:40:11]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jsbell@chromium.org/12780007/6001

[commit-bot: I haz the power, 2013-03-18 16:50:05]

Change committed as 188754