Add GPU command buffer sevice and protobuf to GN build

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 if (is_posix) {
   import("//build/config/gcc/gcc_version.gni")
@@ skipping 685 matching lines @@
   } else {
     # Non-Mac Posix linker flags.
     common_optimize_on_ldflags += [
       # Specifically tell the linker to perform optimizations.
       # See http://lwn.net/Articles/192624/ .
       "-Wl,-O1",
       "-Wl,--as-needed",
       "-Wl,--gc-sections",
     ]
   }
-
-  if (is_android || is_ios) {
-    common_optimize_on_cflags += [ "-Os" ]
-  } else {
-    common_optimize_on_cflags += [ "-O2" ]
-  }
 }
 
 # Default "optimization on" config. On Windows, this favors size over speed.
 config("optimize") {
   cflags = common_optimize_on_cflags
   ldflags = common_optimize_on_ldflags
   if (is_win) {
     cflags += [
       "/Os",   # favor size over speed.
     ]
+  } else if (is_android || is_ios) {
+    cflags += [
+      "-Os",  # Favor size over speed.
+    ]
+  } else {
+    cflags += [
+      "-O2",
+    ]
   }
 }
 
 # Turn off optimizations.
 config("no_optimize") {
   if (is_win) {
     cflags = [
       "/Od",  # Disable optimization.
       "/Ob0",  # Disable all inlining (on by default).
       "/RTC1",  # Runtime checks for stack frame and uninitialized variables.
@@ skipping 17 matching lines @@
 # optimization and link-time code generation which is very expensive and should
 # be used sparingly. For non-Windows, this is the same as "optimize".
 config("optimize_max") {
   cflags = common_optimize_on_cflags
   ldflags = common_optimize_on_ldflags
   if (is_win) {
     cflags += [
       "/Ot",   # Favor speed over size.
       "/GL",   # Whole program optimization.
     ]
+  } else {
+    cflags += [
+      "-O2",
+    ]
   }
 }
 
 # Symbols ----------------------------------------------------------------------
 
 config("symbols") {
   if (is_win) {
     cflags = [ "/Zi" ]  # Produce PDB file, no edit and continue.
     ldflags = [ "/DEBUG" ]
   } else {
     cflags = [ "-g2" ]
   }
 }
 
 config("minimal_symbols") {
   if (is_win) {
     # Linker symbols for backtraces only.
     ldflags = [ "/DEBUG" ]
   } else {
     cflags = [ "-g1" ]
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }