Revert of Use sysroot by default for all linux builds

build/linux/sysroot_scripts/install-sysroot.py

Index: build/linux/sysroot_scripts/install-sysroot.py
diff --git a/build/linux/sysroot_scripts/install-sysroot.py b/build/linux/sysroot_scripts/install-sysroot.py
index 3b47c37352b2f10b2e78be91baeafd3fe9854184..38e8a5179f9d234c6ae8378c3c9f32529dad1c82 100755
--- a/build/linux/sysroot_scripts/install-sysroot.py
+++ b/build/linux/sysroot_scripts/install-sysroot.py
@@ -103,6 +103,28 @@
   return None
 
 
+def UsingSysroot(target_arch, is_android, gyp_defines):
+  # ChromeOS uses a chroot, so doesn't need a sysroot
+  if gyp_defines.get('chromeos'):
+    return False
+
+  # When cross-compiling non-Android builds we always use a sysroot
+  if not is_android and target_arch in ('arm', 'mips', 'i386'):
+    return True
+
+  # Setting use_sysroot=1 GYP_DEFINES forces the use of the sysroot even
+  # when not cross compiling
+  if gyp_defines.get('use_sysroot'):
+    return True
+
+  # Official builds always use the sysroot.
+  if (gyp_defines.get('branding') == 'Chrome' and
+      gyp_defines.get('buildtype') == 'Official'):
+    return True
+
+  return False
+
+
 def main():
   if options.running_as_hook and not sys.platform.startswith('linux'):
     return 0
@@ -111,10 +133,6 @@
   supplemental_includes = gyp_chromium.GetSupplementalFiles()
   gyp_defines = gyp_chromium.GetGypVars(supplemental_includes)
   is_android = gyp_defines.get('OS') == 'android'
-
-  if (options.running_as_hook and (not is_android) and
-      (gyp_defines.get('chromeos') or gyp_defines.get('use_sysroot') == '0')):
-    return 0
 
   if options.arch:
     target_arch = options.arch
@@ -123,6 +141,10 @@
     if not target_arch:
       print 'Unable to detect target architecture'
       return 1
+
+  if (options.running_as_hook and
+      not UsingSysroot(target_arch, is_android, gyp_defines)):
+    return 0
 
   if is_android:
     # 32-bit Android builds require a 32-bit host sysroot for the v8 snapshot.