Linux: reenable malloc overrides.

Linux: reenable malloc overrides.

(These were disabled in r35804 and r35810.)

This time we are using the __libc_* names to get at the real glibc
functions rather than dlsym. This now means that code that calls
__libc_* gets the raw functions, not 'safe' ones. Also, this sets the
visibility correctly. Previously we were not overriding malloc calls
made in shared libraries.

BUG=31809
TEST=Covered by unittests.

[Evan Martin, 2010-01-08 20:23:49]

LGTM

http://codereview.chromium.org/533001/diff/1/2
File base/process_util_linux.cc (right):

http://codereview.chromium.org/533001/diff/1/2#newcode539
base/process_util_linux.cc:539: // for this in process_util_unittest.cc
trailing period

http://codereview.chromium.org/533001/diff/1/2#newcode552
base/process_util_linux.cc:552: // these functions.
I like this fix.

http://codereview.chromium.org/533001/diff/1/2#newcode565
base/process_util_linux.cc:565: void* function_name(arg1_type, size_t)
__attribute__ ((visibility("default"))); \
80, dunno how much you care

[agl, 2010-01-08 21:24:12]

http://codereview.chromium.org/533001/diff/1/2
File base/process_util_linux.cc (right):

http://codereview.chromium.org/533001/diff/1/2#newcode539
base/process_util_linux.cc:539: // for this in process_util_unittest.cc
On 2010/01/08 20:23:49, Evan Martin wrote:
> trailing period

Done.