Desktop Chrome OS: Build with precise sysroot (Reland)

build/config/sysroot.gni

Index: build/config/sysroot.gni
diff --git a/build/config/sysroot.gni b/build/config/sysroot.gni
index b815d2ac6507c0190649b18efba279737b3d9502..70dbb59e6dd933bcade510d682af2ceb7ef0e231 100644
--- a/build/config/sysroot.gni
+++ b/build/config/sysroot.gni
@@ -44,22 +44,26 @@ if (is_linux && target_sysroot_dir != "") {
   } else {
     sysroot = ""
   }
-} else if (is_linux && !is_chromeos && use_sysroot) {
+} else if (is_linux && use_sysroot) {
   # By default build against a sysroot image downloaded from Cloud Storage
   # during gclient runhooks.
-  if (current_cpu == "x64") {
-    sysroot = "//build/linux/debian_wheezy_amd64-sysroot"
-  } else if (current_cpu == "x86") {
-    sysroot = "//build/linux/debian_wheezy_i386-sysroot"
-  } else if (current_cpu == "mipsel") {
-    sysroot = "//build/linux/debian_wheezy_mips-sysroot"
-  } else if (current_cpu == "arm") {
-    sysroot = "//build/linux/debian_wheezy_arm-sysroot"
-  } else if (current_cpu == "arm64") {
-    sysroot = "//build/linux/debian_jessie_arm64-sysroot"
+  if (is_chromeos) {
+    sysroot = "//build/linux/ubuntu_precise_amd64-sysroot"

[Dirk Pranke, 2016/08/25 03:27:22]

add a comment here about why we're using a precise image for this and not some
weird custom sysroot or the default wheezy sysroots (answer is that regular cros
builds use custom sys roots but the "desktop chromeos" case needs to run on the
builders (which are precise) and a cros build depends on things that aren't in
the normal wheezy sysroots).

[Tom (Use chromium acct), 2016/08/25 18:28:51]

Done.

   } else {
-    # Any other builds don't use a sysroot.
-    sysroot = ""
+    if (current_cpu == "x64") {
+      sysroot = "//build/linux/debian_wheezy_amd64-sysroot"
+    } else if (current_cpu == "x86") {
+      sysroot = "//build/linux/debian_wheezy_i386-sysroot"
+    } else if (current_cpu == "mipsel") {
+      sysroot = "//build/linux/debian_wheezy_mips-sysroot"
+    } else if (current_cpu == "arm") {
+      sysroot = "//build/linux/debian_wheezy_arm-sysroot"
+    } else if (current_cpu == "arm64") {
+      sysroot = "//build/linux/debian_jessie_arm64-sysroot"
+    } else {
+      # Any other builds don't use a sysroot.
+      sysroot = ""
+    }
   }
 
   if (sysroot != "") {