Initial commit of profile guided optimization option

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 755d52649725c2bf8ba2c76ceffe5704510542d8..41700d62293c10f9bee14e1413923a82015548f2 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -227,6 +227,12 @@
       # See https://sites.google.com/a/chromium.org/dev/developers/testing/addresssanitizer
       'asan%': 0,
 
+      # Use the provided profiled order file to link Chrome image with it.
+      # This makes Chrome faster by better using CPU cache when executing code.
+      # This is known as PGO (profile guided optimization).
+      # See https://sites.google.com/a/google.com/chrome-msk/dev/boot-speed-up-effort
+      'order_text_section%' : "",
+
       # Set to 1 compile with -fPIC cflag on linux. This is a must for shared
       # libraries on linux x86-64 and arm, plus ASLR.
       'linux_fpic%': 1,
@@ -439,6 +445,7 @@
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'asan%': '<(asan)',
+    'order_text_section%': '<(order_text_section)',
     'enable_register_protocol_handler%': '<(enable_register_protocol_handler)',
     'enable_web_intents%': '<(enable_web_intents)',
     # Whether to build for Wayland display server