[Chromecast] Enable use_sysroot by default for Linux Cast builds.

This CL modifies the Ozone platforms built on Chromecast builds. It
updates the logic in common.gypi to match the logic in ozone.gni.
ozone_platform_gbm still does not build, but this is not needed for our
platform, so this will not be an issue for Cast builds.

BUG=504446
BUG=559708

Bug: b/25865950

Review URL: https://codereview.chromium.org/1477633002

Cr-Commit-Position: refs/heads/master@{#362209}

1 files changed, 7 insertions, 13 deletions

diff --git a/ui/ozone/ozone.gni b/ui/ozone/ozone.gni
index a1fe2f8..8e33f80 100644
--- a/ui/ozone/ozone.gni
+++ b/ui/ozone/ozone.gni
@@ -29,31 +29,25 @@ declare_args() {
   ozone_platform_headless = false
 
   if (ozone_auto_platforms) {
+    # Use headless as the default platform.
+    ozone_platform = "headless"
+    ozone_platform_headless = true
+
     if (is_chromecast) {
-      ozone_platform_headless = true
-      if (disable_display) {
-        # Audio-only builds should use the "headless" platform by default.
-        ozone_platform = "headless"
-      } else {
-        # Builds with video should default to the "cast" platform.
+      if (!disable_display) {
         ozone_platform_cast = true
-        ozone_platform = "cast"
 
-        # For desktop Chromecast builds, override the default "cast" platform with
-        # --ozone_platform=egltest
+        # For desktop Chromecast builds, override the default "headless" platform
+        # with --ozone-platform=egltest
         if (target_os == "linux" && target_cpu != "arm") {
           ozone_platform_egltest = true
           ozone_platform_ozonex = true
         }
       }
     } else {
-      # Use headless as the default platform.
-      ozone_platform = "headless"
-
       # Build all platforms whose deps are in install-build-deps.sh.
       # Only these platforms will be compile tested by buildbots.
       ozone_platform_gbm = true
-      ozone_platform_headless = true
       ozone_platform_egltest = true
     }
   }