Adding METADATA files for prebuilts.

Change-Id: I35e6b79347d2cbf03a867e3f0f42351db043cc15
diff --git a/darwin-x64/ninja/METADATA b/darwin-x64/ninja/METADATA
new file mode 100644
index 0000000..e800bda
--- /dev/null
+++ b/darwin-x64/ninja/METADATA
@@ -0,0 +1,16 @@
+name: "Ninja"
+description: "A small build system."
+
+third_party {
+  url {
+    type: HOMEPAGE
+    value: "https://ninja-build.org/"
+  }
+  url {
+    type: ARCHIVE
+    value: "https://github.com/ninja-build/ninja/releases/download/v1.8.2/ninja-mac.zip"
+  }
+  version: "1.8.2"
+  last_upgrade_date { year: 2018 month: 8 day: 3 }
+  license_type: NOTICE
+}
diff --git a/linux-x64/clang/METADATA b/linux-x64/clang/METADATA
new file mode 100644
index 0000000..83993b0
--- /dev/null
+++ b/linux-x64/clang/METADATA
@@ -0,0 +1,16 @@
+name: "Clang"
+description: "A C language family frontend for LLVM."
+
+third_party {
+  url {
+    type: HOMEPAGE
+    value: "https://clang.llvm.org/"
+  }
+  url {
+    type: GIT
+    value: "https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86/+/master/clang-r344140b/"
+  }
+  version: "8.0.4"
+  last_upgrade_date { year: 2018 month: 11 day: 16 }
+  license_type: NOTICE
+}
diff --git a/linux-x64/clang/README.md b/linux-x64/clang/README.md
index 6b1df1e..1d03fd0 100644
--- a/linux-x64/clang/README.md
+++ b/linux-x64/clang/README.md
@@ -1,2 +1,2 @@
-This is the `clang-r339409b` directory from
+This is the `clang-r344140b` directory from
 https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86/
diff --git a/linux-x64/gn/METADATA b/linux-x64/gn/METADATA
new file mode 100644
index 0000000..9c5aee5
--- /dev/null
+++ b/linux-x64/gn/METADATA
@@ -0,0 +1,12 @@
+name: "GN"
+description: "GN is a meta-build system that generates NinjaBuild files."
+
+third_party {
+  url {
+    type: GIT
+    value: "https://gn.googlesource.com/gn"
+  }
+  version: "1452"
+  last_upgrade_date { year: 2018 month: 8 day: 3 }
+  license_type: NOTICE
+}
diff --git a/linux-x64/ninja/METADATA b/linux-x64/ninja/METADATA
new file mode 100644
index 0000000..e8c81d0
--- /dev/null
+++ b/linux-x64/ninja/METADATA
@@ -0,0 +1,16 @@
+name: "Ninja"
+description: "A small build system."
+
+third_party {
+  url {
+    type: HOMEPAGE
+    value: "https://ninja-build.org/"
+  }
+  url {
+    type: ARCHIVE
+    value: "https://github.com/ninja-build/ninja/releases/download/v1.8.2/ninja-linux.zip"
+  }
+  version: "1.8.2"
+  last_upgrade_date { year: 2018 month: 8 day: 3 }
+  license_type: NOTICE
+}
diff --git a/linux-x64/qemu/METADATA b/linux-x64/qemu/METADATA
new file mode 100644
index 0000000..39af6ab
--- /dev/null
+++ b/linux-x64/qemu/METADATA
@@ -0,0 +1,16 @@
+name: "QEMU"
+description: "A C language family frontend for LLVM."
+
+third_party {
+  url {
+    type: HOMEPAGE
+    value: "https://www.qemu.org/"
+  }
+  url {
+    type: ARCHIVE
+    value: "https://download.qemu.org/qemu-2.12.1.tar.xz"
+  }
+  version: "2.12.1"
+  last_upgrade_date { year: 2018 month: 8 day: 9 }
+  license_type: RESTRICTED
+}