Update BUILD.gn for [P]NaCl.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 3e8496e0f22a666e798b8c3c2eed569b39a0b74f..7c82d8c60b8c19acfb9dd94e27614de4b2060b05 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -10,6 +10,8 @@ import("//third_party/yasm/yasm_assemble.gni")
 
 if (is_posix && !is_mac) {
   os_category = "linux"
+} if (is_nacl) {

[Johann, 2015/09/03 02:14:51]

this doesn't seem necessary, but if you want to keep it should it be else if?

[Sergey Ulanov, 2015/09/03 04:25:20]

Actually with your other suggestion below os_category is not used in is_nacl
case, so I moved os_category inside !is_nacl if block below.

+  os_category = "nacl"
 } else {
   os_category = current_os
 }
@@ -35,10 +37,18 @@ if (current_cpu == "x86") {
   cpu_arch_full = current_cpu
 }
 
+if (os_category == "nacl") {

[Johann, 2015/09/03 02:14:51]

this could be if(is_nacl), yeah?

[Sergey Ulanov, 2015/09/03 04:25:20]

Done.

+  platform_include_dir =
+      "//third_party/libvpx/source/config/$os_category"

[Johann, 2015/09/03 02:14:51]

this could be hard coded source/config/nacl

[Sergey Ulanov, 2015/09/03 04:25:20]

Done.

+} else {
+  platform_include_dir =
+      "//third_party/libvpx/source/config/$os_category/$cpu_arch_full"
+}
+
 config("libvpx_config") {
   include_dirs = [
     "//third_party/libvpx/source/config",
-    "//third_party/libvpx/source/config/$os_category/$cpu_arch_full",
+    platform_include_dir,
     "//third_party/libvpx/source/libvpx",
     "$root_gen_dir/third_party/libvpx", # Provides vpx_rtcd.h.
   ]
@@ -77,9 +87,9 @@ if (current_cpu == "x86" || current_cpu == "x64") {
 
     defines = [ "CHROMIUM" ]
     include_dirs = [
-      "//third_party/libvpx/source/config/$os_category/$cpu_arch_full",
+      platform_include_dir,
       "//third_party/libvpx/source/config",
-     "//third_party/libvpx/source/libvpx",
+      "//third_party/libvpx/source/libvpx",
       target_gen_dir
     ]
   }
@@ -214,7 +224,9 @@ static_library("libvpx") {
     configs += [ "//build/config/compiler:optimize_max" ]
   }
 
-  if (current_cpu == "x86") {
+  if (is_nacl) {
+    sources = libvpx_srcs_generic
+  } if (current_cpu == "x86") {

[Johann, 2015/09/03 02:14:51]

else if?

[Sergey Ulanov, 2015/09/03 04:25:20]

Yes, of course! Thanks for catching it! 

     sources = libvpx_srcs_x86
   } else if (current_cpu == "x64") {
     if (is_msan) {