Switching from the old (CLD2) to the new (CLD3) language detector.

Note:
I ran tools/linux/dump-static-initializers.py on CLD3. It did not find any static initializers.

BUG=624904

Review-Url: https://codereview.chromium.org/2244683002
Cr-Commit-Position: refs/heads/master@{#411677}

third_party/cld/BUILD.gn

@@ -5,7 +5,7 @@
 import("//build/buildflag_header.gni")
 
 # Specifies which language identification model to use: CLD2 or CLD3.
-cld_version = 2
+cld_version = 3
 
 buildflag_header("cld_version") {
   header = "cld_version.h"