Fix build with variants enabled

When build variants are enabled (even if they're not used for this
driver) executables may be built inside a "novariant" toolchain. That
wasn't accounted for correctly in the paths, so in particular we need to
switch to using root_build_dir instead of root_out_dir for finding
files. We also need to explicitly mention the toolchain.

Change-Id: I6b019bad887d77dad994bb12eb473775de423365
diff --git a/fuchsia/BUILD.gn b/fuchsia/BUILD.gn
index eab441b..7decf24 100644
--- a/fuchsia/BUILD.gn
+++ b/fuchsia/BUILD.gn
@@ -10,7 +10,7 @@
   intel_media_driver_debug = is_debug
 }
 
-va_install_root = "$root_out_dir/build-intel-media-driver/install"
+va_install_root = "$root_build_dir/build-intel-media-driver/install"
 
 config("va-config") {
   include_dirs = [ "$va_install_root/include" ]
@@ -93,30 +93,30 @@
     depfile = "$root_out_dir/build-intel-media-driver/media-driver.d"
     no_output_dir_leaks = false
   }
-}
 
-build_id_entry("libva_build_id") {
-  stripped = "$va_install_root/strip/libva.so.2"
-  debug = "$va_install_root/strip/libva.so.2.debug"
-  deps = [ ":out-of-tree-build" ]
-}
+  build_id_entry("libva_build_id") {
+    stripped = "$va_install_root/strip/libva.so.2"
+    debug = "$va_install_root/strip/libva.so.2.debug"
+    deps = [ ":out-of-tree-build" ]
+  }
 
-build_id_entry("libva_magma_build_id") {
-  stripped = "$va_install_root/strip/libva-magma.so.2"
-  debug = "$va_install_root/strip/libva-magma.so.2.debug"
-  deps = [ ":out-of-tree-build" ]
-}
+  build_id_entry("libva_magma_build_id") {
+    stripped = "$va_install_root/strip/libva-magma.so.2"
+    debug = "$va_install_root/strip/libva-magma.so.2.debug"
+    deps = [ ":out-of-tree-build" ]
+  }
 
-build_id_entry("libigdgmm_build_id") {
-  stripped = "$va_install_root/strip/libigdgmm.so.11"
-  debug = "$va_install_root/strip/libigdgmm.so.11.debug"
-  deps = [ ":out-of-tree-build" ]
-}
+  build_id_entry("libigdgmm_build_id") {
+    stripped = "$va_install_root/strip/libigdgmm.so.11"
+    debug = "$va_install_root/strip/libigdgmm.so.11.debug"
+    deps = [ ":out-of-tree-build" ]
+  }
 
-build_id_entry("iHD_build_id") {
-  stripped = "$va_install_root/strip/iHD_drv_video.so"
-  debug = "$va_install_root/strip/iHD_drv_video.so.debug"
-  deps = [ ":out-of-tree-build" ]
+  build_id_entry("iHD_build_id") {
+    stripped = "$va_install_root/strip/iHD_drv_video.so"
+    debug = "$va_install_root/strip/iHD_drv_video.so.debug"
+    deps = [ ":out-of-tree-build" ]
+  }
 }
 
 group("va-intel") {
@@ -127,11 +127,11 @@
     ":va-magma",
   ]
   deps = [
-    ":iHD_build_id",
-    ":libigdgmm_build_id",
-    ":libva_build_id",
-    ":libva_magma_build_id",
-    ":out-of-tree-build",
+    ":iHD_build_id($default_toolchain)",
+    ":libigdgmm_build_id($default_toolchain)",
+    ":libva_build_id($default_toolchain)",
+    ":libva_magma_build_id($default_toolchain)",
+    ":out-of-tree-build($default_toolchain)",
   ]
 }
 
@@ -139,9 +139,9 @@
   output_name = "codec_runner_intel_gen"
   sources = [ "main.cc" ]
   deps = [
-    "//src/media/codec/codecs/vaapi:codec_runner_vaapi",
     ":va-intel",
     "//src/graphics/lib/magma/src/libmagma",
+    "//src/media/codec/codecs/vaapi:codec_runner_vaapi",
   ]
 }