[Merge M-56] Return cached query result for canMakeActivePayment.

[Merge M-56] Return cached query result for canMakeActivePayment.

The PaymentRequest.canMakeActivePayment() feature, which is currently
hidden behind a flag, throttles queries of supported methods to reduce
the risk of user fingerprinting. Since the upcoming (not yet
implemented) 'basic-card' method can be used with different subsets of
card networks ('visa', 'mastercard', etc.) and types ('credit', 'debit',
'prepaid'), this patch changes canMakeActivePayment() to return last
cached result instead of re-querying every time. This also happens to be
more inline with the proposed specification language:

"Multiple calls to canMakeActivePayment will result in cached response
from previous call."

Proposed PaymentRequest.canMakeActivePayment() specification:
https://github.com/w3c/browser-payment-api/pull/316/files

BUG=662931
Review-Url: https://codereview.chromium.org/2507063009
Cr-Commit-Position: refs/heads/master@{#433689}
(cherry picked from commit 639ffbbca80f848266bb78f5ce28f0eddc7649fd)

Committed: https://chromium.googlesource.com/chromium/src/+/9296d6865e182c85bac474630f7cb09b07c2b346

[please use gerrit instead, 2016-11-22 14:52:35]

Description was changed from

==========
[Merge M-56] Return cached query result for canMakeActivePayment.

The PaymentRequest.canMakeActivePayment() feature, which is currently
hidden behind a flag, throttles queries of supported methods to reduce
the risk of user fingerprinting. Since the upcoming (not yet
implemented) 'basic-card' method can be used with different subsets of
card networks ('visa', 'mastercard', etc.) and types ('credit', 'debit',
'prepaid'), this patch changes canMakeActivePayment() to return last
cached result instead of re-querying every time. This also happens to be
more inline with the proposed specification language:

"Multiple calls to canMakeActivePayment will result in cached response
from previous call."

Proposed PaymentRequest.canMakeActivePayment() specification:
https://github.com/w3c/browser-payment-api/pull/316/files

BUG=662931

Review-Url: https://codereview.chromium.org/2507063009
Cr-Commit-Position: refs/heads/master@{#433689}
(cherry picked from commit 639ffbbca80f848266bb78f5ce28f0eddc7649fd)
==========

to

==========
[Merge M-56] Return cached query result for canMakeActivePayment.

The PaymentRequest.canMakeActivePayment() feature, which is currently
hidden behind a flag, throttles queries of supported methods to reduce
the risk of user fingerprinting. Since the upcoming (not yet
implemented) 'basic-card' method can be used with different subsets of
card networks ('visa', 'mastercard', etc.) and types ('credit', 'debit',
'prepaid'), this patch changes canMakeActivePayment() to return last
cached result instead of re-querying every time. This also happens to be
more inline with the proposed specification language:

"Multiple calls to canMakeActivePayment will result in cached response
from previous call."

Proposed PaymentRequest.canMakeActivePayment() specification:
https://github.com/w3c/browser-payment-api/pull/316/files

BUG=662931

Review-Url: https://codereview.chromium.org/2507063009
Cr-Commit-Position: refs/heads/master@{#433689}
(cherry picked from commit 639ffbbca80f848266bb78f5ce28f0eddc7649fd)

Committed:
https://chromium.googlesource.com/chromium/src/+/9296d6865e182c85bac474630f7c...
==========

[please use gerrit instead, 2016-11-22 14:52:37]

Committed patchset #1 (id:1) manually as
9296d6865e182c85bac474630f7cb09b07c2b346.