Update from https://crrev.com/327068

This rolls in //base, //build and //sandbox/linux and updates other
things to match, in particular:

*) Update build_v8.patch
*) Add junit, mockito and roboelectric to DEPS for android test rules
*) Update DEPS for grit
*) Fix up various GN files for os->target_os rename
*) Fix up a few places that were using //base/float_util to use std::isnan
*) Fix up a few places using ApiCompatibilityUtil to use Android SDK directly

as well as a few miscellaneous fixes.

Many portions based on ncbray's work in
https://codereview.chromium.org/1108173002/

R=ncbray@chromium.org
TBR=ncbray@chromium.org

Review URL: https://codereview.chromium.org/1124763003
diff --git a/third_party/libxml/DEPS b/third_party/libxml/DEPS
new file mode 100644
index 0000000..6dcfa15
--- /dev/null
+++ b/third_party/libxml/DEPS
@@ -0,0 +1,3 @@
+include_rules = [
+  '+libxml',
+]