Rename is_chromeos in chrome/src.

content/common/BUILD.gn

Index: content/common/BUILD.gn
diff --git a/content/common/BUILD.gn b/content/common/BUILD.gn
index 17113e25a06a8099d7765d9d69f7964705dd648d..6c1decc0689a167f2a93de0b98f0bc1235b2f6b9 100644
--- a/content/common/BUILD.gn
+++ b/content/common/BUILD.gn
@@ -10,7 +10,7 @@ if (is_mac) {
   import("//build/config/mac/mac_sdk.gni")
 }
 
-if (is_chromeos && current_cpu != "arm") {
+if (use_cros_fe && current_cpu != "arm") {
   action("libva_generate_stubs") {
     extra_header = "gpu/media/va_stub_header.fragment"
 
@@ -52,7 +52,7 @@ if (is_chromeos && current_cpu != "arm") {
   }
 }
 
-if (is_chromeos && use_v4lplugin) {
+if (use_cros_fe && use_v4lplugin) {
   action("libv4l2_generate_stubs") {
     extra_header = "gpu/media/v4l2_stub_header.fragment"
 
@@ -310,7 +310,7 @@ source_set("common") {
       "//third_party/khronos:khronos_headers",
     ]
 
-    if (current_cpu != "arm" || !is_chromeos) {
+    if (current_cpu != "arm" || !use_cros_fe) {
       sources += [ "gpu/x_util.h" ]
     }
   }
@@ -344,7 +344,7 @@ source_set("common") {
     }
   }
 
-  if (is_chromeos) {
+  if (use_cros_fe) {
     sources += [
       "gpu/media/accelerated_video_decoder.h",
       "gpu/media/h264_decoder.cc",