Mojo C++ bindings: better log messages for some validation errors at the receiver side.

Mojo C++ bindings: better log messages for some validation errors at the receiver side.

The CL provides more information in the log messages for the following errors:
- Fixed-size array has wrong number of elements.
- non-nullable field is set to null/invalid handle.

The reason to have better log messages for these errors is that they are
triggered when users (of the bindings) provide invalid arguments. The users
probably want to find out what they have done wrong. The other validation errors
are rarer, caused by bugs in the bindings or malicious senders. Providing better
log messages for them is of slightly lower priority.

BUG=324170
TEST=None

Committed: https://crrev.com/90017b5f151ca42ffd7a14cfc2eaa08370da9fae
Cr-Commit-Position: refs/heads/master@{#291704}

[yzshen1, 2014-08-21 07:17:59]

Hi, Darin.

Would you please take a look? Thanks!

This CL depends on https://codereview.chromium.org/473793004/

[darin (slow to review), 2014-08-21 23:56:52]

LGTM

[yzshen1, 2014-08-22 00:07:14]

The CQ bit was checked by yzshen@chromium.org

[commit-bot: I haz the power, 2014-08-22 00:09:14]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/yzshen@chromium.org/494943004/20001

[commit-bot: I haz the power, 2014-08-22 01:10:06]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)
  win_chromium_compile_dbg on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_comp...)

[commit-bot: I haz the power, 2014-08-22 02:06:32]

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

[commit-bot: I haz the power, 2014-08-22 02:06:33]

Try jobs failed on following builders:
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[yzshen1, 2014-08-22 02:46:24]

The CQ bit was checked by yzshen@chromium.org

[commit-bot: I haz the power, 2014-08-22 02:47:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/yzshen@chromium.org/494943004/20001

[commit-bot: I haz the power, 2014-08-22 03:41:07]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[commit-bot: I haz the power, 2014-08-22 04:36:03]

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

[commit-bot: I haz the power, 2014-08-22 04:36:04]

Try jobs failed on following builders:
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[yzshen1, 2014-08-25 16:33:35]

The CQ bit was checked by yzshen@chromium.org

[commit-bot: I haz the power, 2014-08-25 16:34:32]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/yzshen@chromium.org/494943004/20001

[commit-bot: I haz the power, 2014-08-25 17:28:28]

Committed patchset #2 (20001) as 87bda7783c7ab69ad05024ba98a7aae4c4a6821c

[commit-bot: I haz the power, 2014-09-10 02:35:19]

Patchset 2 (id:??) landed as
https://crrev.com/90017b5f151ca42ffd7a14cfc2eaa08370da9fae
Cr-Commit-Position: refs/heads/master@{#291704}