Mojo C++ bindings: fix sanity check of wtf string serialization.

Mojo C++ bindings: fix sanity check of wtf string serialization.

Previously the code had a check that we use exactly the same WTF::String object
for GetSerializedSize_ and Serialize_ call. However, because WTF::String is
ref-counted, we may end up using different WTF::String objects referring to the
same contents. That may happen, e.g., when moving WTF::String to a different
container.

This CL changes the sanity check to verify that the size of WTF::String remains
unchanged.

BUG=595791
Committed: https://crrev.com/ff43dcf4c622fb46b062abca1024a89fb01b54c7
Cr-Commit-Position: refs/heads/master@{#381880}

[yzshen1, 2016-03-18 02:18:42]

Description was changed from

==========
Mojo C++ bindings: fix sanity check of wtf string serialization.

Previously the code has a sanity check that we use the same WTF::String object
for GetSerializedSize_ and Serialize_ call. However, because WTF::String is
ref-counted, we may end up using different WTF::String objects refering to the
same contents. That may happen, e.g., when moving WTF::String to a different
container.

This CL changes the sanity check to verify that the size of WTF::String remains
unchanged.

BUG=595791
==========

to

==========
Mojo C++ bindings: fix sanity check of wtf string serialization.

Previously the code had a check that we use exactly the same WTF::String object
for GetSerializedSize_ and Serialize_ call. However, because WTF::String is
ref-counted, we may end up using different WTF::String objects referring to the
same contents. That may happen, e.g., when moving WTF::String to a different
container.

This CL changes the sanity check to verify that the size of WTF::String remains
unchanged.

BUG=595791
==========

[yzshen1, 2016-03-18 02:18:42]

yzshen@chromium.org changed reviewers:
+ rockot@chromium.org

[yzshen1, 2016-03-18 02:19:03]

Hi, Ken.

Would you please take a look? Thanks!

[yzshen1, 2016-03-18 02:19:03]

Hi, Ken.

Would you please take a look? Thanks!

[Ken Rockot(use gerrit already), 2016-03-18 02:40:19]

I don't fully understand this - how can it happen that a WTF::String moves to a
different container in the middle of serialization? Is there an example?

[yzshen1, 2016-03-18 02:46:22]

On 2016/03/18 02:40:19, Ken Rockot wrote:
> I don't fully understand this - how can it happen that a WTF::String moves to
a
> different container in the middle of serialization? Is there an example?

For example: we have a mojo::WTFArray<WTF::String> arr.

GetSerializedSize_(arr) -- which passes a const ref of the array to the
function;
SerializeArray_(std::move(arr)) -- which moves the array.

[Ken Rockot(use gerrit already), 2016-03-18 02:47:53]

I see! Subtle. LGTM

[yzshen1, 2016-03-18 02:49:11]

The CQ bit was checked by yzshen@chromium.org

[commit-bot: I haz the power, 2016-03-18 02:49:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1810253002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1810253002/1

[commit-bot: I haz the power, 2016-03-18 03:19:57]

Description was changed from

==========
Mojo C++ bindings: fix sanity check of wtf string serialization.

Previously the code had a check that we use exactly the same WTF::String object
for GetSerializedSize_ and Serialize_ call. However, because WTF::String is
ref-counted, we may end up using different WTF::String objects referring to the
same contents. That may happen, e.g., when moving WTF::String to a different
container.

This CL changes the sanity check to verify that the size of WTF::String remains
unchanged.

BUG=595791
==========

to

==========
Mojo C++ bindings: fix sanity check of wtf string serialization.

Previously the code had a check that we use exactly the same WTF::String object
for GetSerializedSize_ and Serialize_ call. However, because WTF::String is
ref-counted, we may end up using different WTF::String objects referring to the
same contents. That may happen, e.g., when moving WTF::String to a different
container.

This CL changes the sanity check to verify that the size of WTF::String remains
unchanged.

BUG=595791
==========

[commit-bot: I haz the power, 2016-03-18 03:19:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-18 03:21:44]

Description was changed from

==========
Mojo C++ bindings: fix sanity check of wtf string serialization.

Previously the code had a check that we use exactly the same WTF::String object
for GetSerializedSize_ and Serialize_ call. However, because WTF::String is
ref-counted, we may end up using different WTF::String objects referring to the
same contents. That may happen, e.g., when moving WTF::String to a different
container.

This CL changes the sanity check to verify that the size of WTF::String remains
unchanged.

BUG=595791
==========

to

==========
Mojo C++ bindings: fix sanity check of wtf string serialization.

Previously the code had a check that we use exactly the same WTF::String object
for GetSerializedSize_ and Serialize_ call. However, because WTF::String is
ref-counted, we may end up using different WTF::String objects referring to the
same contents. That may happen, e.g., when moving WTF::String to a different
container.

This CL changes the sanity check to verify that the size of WTF::String remains
unchanged.

BUG=595791

Committed: https://crrev.com/ff43dcf4c622fb46b062abca1024a89fb01b54c7
Cr-Commit-Position: refs/heads/master@{#381880}
==========

[commit-bot: I haz the power, 2016-03-18 03:21:46]

Patchset 1 (id:??) landed as
https://crrev.com/ff43dcf4c622fb46b062abca1024a89fb01b54c7
Cr-Commit-Position: refs/heads/master@{#381880}