Get rid of base::SharedMemory::NULLHandle();
This CL is a refactor and has no intended behavior change.
NullHandle() has two use cases:
* Create an invalid handle.
* Return an object that can be compared against a handle to check validity.
The former is also the behavior of the default constructor of
base::SharedMemoryHandle, and the latter should be done with the member
IsValid().
Fixing the latter also allows the removal of operator== and operator!=.
BUG=713763
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Review-Url: https://codereview.chromium.org/2849633002
Cr-Commit-Position: refs/heads/master@{#468231}
36 files changed
