Fix breakpad for arm on arm64

Fix breakpad for arm on arm64

On arm64 devices, GETFPREGS fails with errno==EIO. Ignore those failures
on Android arm builds.

BUG=508324
R=thestig@chromium.org

Committed: https://code.google.com/p/google-breakpad/source/detail?r=1479

[cjhopman, 2015-08-03 23:43:28]

cjhopman@chromium.org changed reviewers:
+ thestig@chromium.org

[cjhopman, 2015-08-03 23:43:28]

thestig: *

[Lei Zhang, 2015-08-04 00:11:33]

https://codereview.chromium.org/1268023003/diff/1/client/linux/minidump_write...
File client/linux/minidump_writer/linux_ptrace_dumper.cc (right):

https://codereview.chromium.org/1268023003/diff/1/client/linux/minidump_write...
client/linux/minidump_writer/linux_ptrace_dumper.cc:209: void* fp_addr;
- I would just skip this entire block on Android + ARM EABI.
-- BTW, with these #defines, the address |fp_addr| points to is not read in
client/linux/dump_writer_common/thread_info.cc.

- If you can add a comment here to reference a bug, that'll save on future code
archaeology time.

[cjhopman, 2015-08-04 23:28:45]

https://codereview.chromium.org/1268023003/diff/1/client/linux/minidump_write...
File client/linux/minidump_writer/linux_ptrace_dumper.cc (right):

https://codereview.chromium.org/1268023003/diff/1/client/linux/minidump_write...
client/linux/minidump_writer/linux_ptrace_dumper.cc:209: void* fp_addr;
On 2015/08/04 00:11:33, Lei Zhang wrote:
> - I would just skip this entire block on Android + ARM EABI.
> -- BTW, with these #defines, the address |fp_addr| points to is not read in
> client/linux/dump_writer_common/thread_info.cc.
> 
> - If you can add a comment here to reference a bug, that'll save on future
code
> archaeology time.

Done.

[Lei Zhang, 2015-08-04 23:39:34]

lgtm

https://codereview.chromium.org/1268023003/diff/20001/client/linux/minidump_w...
File client/linux/minidump_writer/linux_ptrace_dumper.cc (right):

https://codereview.chromium.org/1268023003/diff/20001/client/linux/minidump_w...
client/linux/minidump_writer/linux_ptrace_dumper.cc:220: #endif
nit: add // PTRACE_GETREGSET so it's more obvious whaat the matching #ifdef is.

[cjhopman, 2015-08-05 22:48:53]

Committed patchset #2 (id:20001) manually as 1479 (presubmit successful).