Move ChromiumMultiDex to BuildConfig.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index fc441da12ded089e232797d9dffb0d0bf4a1442c..d293d082f79dc83e29032856ce7474e6f61601f8 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -2046,7 +2046,7 @@ if (is_android) {
   android_library("base_java") {
     srcjar_deps = [
       ":base_android_java_enums_srcjar",
-      ":base_multidex_gen",
+      ":base_chromium_build_config_gen",
       ":base_native_libraries_gen",
     ]
 
@@ -2057,10 +2057,10 @@ if (is_android) {
 
     DEPRECATED_java_in_dir = "android/java/src"
 
-    # New versions of ChromiumMultiDex.java and NativeLibraries.java
+    # New versions of ChromiumBuildConfig.java and NativeLibraries.java
     # (with the actual correct values) will be created when creating an apk.
     jar_excluded_patterns = [
-      "*/ChromiumMultiDex.class",
+      "*/ChromiumBuildConfig.class",
       "*/NativeLibraries.class",
       "*/NativeLibraries##*.class",
     ]
@@ -2095,7 +2095,7 @@ if (is_android) {
       "//third_party/robolectric:android-all-4.3_r2-robolectric-0",
       "//third_party/robolectric:robolectric_java",
     ]
-    srcjar_deps = [ ":base_multidex_gen" ]
+    srcjar_deps = [ ":base_chromium_build_config_gen" ]
   }
 
   # GYP: //base.gyp:base_junit_tests
@@ -2125,12 +2125,12 @@ if (is_android) {
     ]
   }
 
-  # GYP: //base/base.gyp:base_multidex_gen
-  java_cpp_template("base_multidex_gen") {
+  # GYP: //base/base.gyp:base_chromium_build_config_gen
+  java_cpp_template("base_chromium_build_config_gen") {
     sources = [
-      "android/java/templates/ChromiumMultiDex.template",
+      "android/java/templates/ChromiumBuildConfig.template",
     ]
-    package_name = "org/chromium/base/multidex"
+    package_name = "org/chromium/base"
   }
 
   # GYP: //base/base.gyp:base_native_libraries_gen