GitLab

Fuchsia cares about binary size, like iOS and Android. This configures
the default build to -Oz instead of -O2.  This reduces the size of text
segment of the service_exe webrunner executable by about 13% when
building for ARM64 release mode non-component:

O2:
   text    data     bss     dec     hex filename
83509089        3370852 1109788a 87989729        53e9de1 out/fuchsia_arm64/exe.unstripped/service_exe

   text    data     bss     dec     hex filename
73707333        3398764 1110516 78216613        4a97da5 out/fuchsia_arm64/exe.unstripped/service_exe

Oz: 
Change-Id: I09774eb71f690a483f3f6064cace265a7f7f80e6
Reviewed-on: https://chromium-review.googlesource.com/1171864Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582460}