android: use "after inlining" function instrumentation.

85023f02 rolled clang past r318199
adding an option to insert instrumentation calls after inlining. This
drastically decreases the instrumented build size:

before:
-rwxr-x--- 1 lizeb eng 257M Nov 29 14:20 libchrome.so*

after:
-rwxr-x--- 1 lizeb eng 67M Nov 29 14:49 libchrome.so*

This should reduce compilation time on the orderfile bot.

Bug: 776702
Change-Id: I37549e5f6611286ff09238d428b05458f8f2397c
Reviewed-on: https://chromium-review.googlesource.com/796478Reviewed-by: agrieve <agrieve@chromium.org>
Reviewed-by: Egor Pasko <pasko@chromium.org>
Reviewed-by: Matthew Cary <mattcary@chromium.org>
Commit-Queue: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520626}

build/config/android/BUILD.gn

@@ -211,7 +211,7 @@ config("default_cygprofile_instrumentation") {
 
 config("cygprofile_instrumentation") {
   defines = [ "CYGPROFILE_INSTRUMENTATION=1" ]
-  cflags = [ "-finstrument-functions" ]
+  cflags = [ "-finstrument-functions-after-inlining" ]
 }
 
 config("no_cygprofile_instrumentation") {