Add a new CldDataSource class that can be queried at runtime.

components/translate/content/common/BUILD.gn

Index: components/translate/content/common/BUILD.gn
diff --git a/components/translate/content/common/BUILD.gn b/components/translate/content/common/BUILD.gn
index 012504610d4aa184f5b2fdf5b57bed8aa695fa58..44affb39e6d0285ae2b94ddc9bcffe74685bc8bc 100644
--- a/components/translate/content/common/BUILD.gn
+++ b/components/translate/content/common/BUILD.gn
@@ -8,6 +8,7 @@ static_library("common") {
   sources = [
     "translate_messages.cc",
     "translate_messages.h",
+    "cld_data_source.h",
   ]
 
   deps = [
@@ -24,4 +25,13 @@ static_library("common") {
       "data_file_cld_data_provider_messages.h",
     ]
   }
+  if (cld2_data_source == "standalone") {
+    sources += [ "standalone_cld_data_source.cc" ]
+  }
+  if (cld2_data_source == "component") {
+    sources += [ "component_cld_data_source.cc" ]
+  }
+  if (cld2_data_source == "static") {
+    sources += [ "static_cld_data_source.cc" ]
+  }
 }