Extension content verification: new class for parsing data from store

Add a class for parsing extension content verification data

The webstore will be vending a "verified_contents.json" file for
extensions hosted there that contains a signed list of expected
block hashes for the files contained in an extension.

This new class handles parsing/validation of that data.

BUG=369895
R=rockot@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=269305

[Ken Rockot(use gerrit already), 2014-05-08 20:05:17]

Nice. LGTM w/nit

https://codereview.chromium.org/278593005/diff/1/extensions/browser/verified_...
File extensions/browser/verified_contents.h (right):

https://codereview.chromium.org/278593005/diff/1/extensions/browser/verified_...
extensions/browser/verified_contents.h:23: VerifiedContents(const uint8*
public_key, int public_key_size);
nit: I'm a little wary of constructing this over a raw pointer and hanging onto
its value. Since it is retained and used, are you opposed to copying the data
into an owned vector<uint8>? If so, maybe at least document that the key is not
owned and that the pointee must outlive the VerifiedContents.

[asargent_no_longer_on_chrome, 2014-05-08 21:05:45]

https://codereview.chromium.org/278593005/diff/1/extensions/browser/verified_...
File extensions/browser/verified_contents.h (right):

https://codereview.chromium.org/278593005/diff/1/extensions/browser/verified_...
extensions/browser/verified_contents.h:23: VerifiedContents(const uint8*
public_key, int public_key_size);
On 2014/05/08 20:05:17, Ken Rockot wrote:
> nit: I'm a little wary of constructing this over a raw pointer and hanging
onto
> its value. Since it is retained and used, are you opposed to copying the data
> into an owned vector<uint8>? If so, maybe at least document that the key is
not
> owned and that the pointee must outlive the VerifiedContents.

This is going to be used in some performance sensitive code and I want to avoid
copying, so I've added a comment. In practice, we'll using a constant for this,
but it's going to be defined in chrome/ instead of extensions/ "because
componentization" and I'm going to have to pass it though a few layers to get
here.

[asargent_no_longer_on_chrome, 2014-05-08 21:05:48]

The CQ bit was checked by asargent@chromium.org

[commit-bot: I haz the power, 2014-05-08 21:07:37]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/asargent@chromium.org/278593005/20001

[commit-bot: I haz the power, 2014-05-09 01:31:31]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  win_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_compile_...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)
  win_chromium_x64_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_x64_rel/...)

[commit-bot: I haz the power, 2014-05-09 03:19:24]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-05-09 03:19:29]

Try jobs failed on following builders:
  win_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_compile_...)
  win_chromium_x64_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_x64_rel/...)

[asargent_no_longer_on_chrome, 2014-05-09 04:56:04]

The CQ bit was checked by asargent@chromium.org

[commit-bot: I haz the power, 2014-05-09 05:03:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/asargent@chromium.org/278593005/30001

[commit-bot: I haz the power, 2014-05-09 11:24:43]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  win_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_compile_...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)
  win_chromium_x64_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_x64_rel/...)

[commit-bot: I haz the power, 2014-05-09 13:46:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-05-09 13:46:01]

Try jobs failed on following builders:
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)