[Android] Rework multidex and enable multidex for unit_tests_apk.

base/android/java/src/org/chromium/base/multidex/ChromiumMultiDexInstaller.java

Index: base/android/java/src/org/chromium/base/multidex/ChromiumMultiDexInstaller.java
diff --git a/base/android/java/templates/ChromiumMultiDex.template b/base/android/java/src/org/chromium/base/multidex/ChromiumMultiDexInstaller.java
similarity index 94%
copy from base/android/java/templates/ChromiumMultiDex.template
copy to base/android/java/src/org/chromium/base/multidex/ChromiumMultiDexInstaller.java
index 5580489cd53980d322d294713f10dcbdc7143f65..e4b30b94685fcd8c421df57be95c1217bf8ead86 100644
--- a/base/android/java/templates/ChromiumMultiDex.template
+++ b/base/android/java/src/org/chromium/base/multidex/ChromiumMultiDexInstaller.java
@@ -10,7 +10,6 @@ import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.os.Build;
-import android.os.Process;
 import android.support.multidex.MultiDex;
 
 import org.chromium.base.Log;
@@ -22,7 +21,7 @@ import java.lang.reflect.Method;
 /**
  *  Performs multidex installation for non-isolated processes.
  */
-public class ChromiumMultiDex {
+public class ChromiumMultiDexInstaller {
 
     private static final String TAG = "base_multidex";
 
@@ -38,7 +37,7 @@ public class ChromiumMultiDex {
      *  Isolated processes (e.g. renderer processes) can't load secondary dex files on
      *  K and below, so we don't even try in that case.
      *
-     *  In release builds, this is a no-op because:
+     *  In release builds of app apks (as opposed to test apks), this is a no-op because:
      *    - multidex isn't necessary in release builds because we run proguard there and
      *      thus aren't threatening to hit the dex limit; and
      *    - calling MultiDex.install, even in the absence of secondary dexes, causes a
@@ -47,8 +46,9 @@ public class ChromiumMultiDex {
      *  @param context The application context.
      */
     @VisibleForTesting
-#if defined(MULTIDEX_CONFIGURATION_Debug)
     public static void install(Context context) {
+        if (!ChromiumMultiDex.isMultidexEnabled()) return;
+
         // TODO(jbudorick): Back out this version check once support for K & below works.
         // http://crbug.com/512357
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP
@@ -83,7 +83,7 @@ public class ChromiumMultiDex {
     // Determines whether MultiDex should be installed for the current process.  Isolated
     // Processes should skip MultiDex as they can not actually access the files on disk.
     // Privileged processes need ot have all of their dependencies in the MainDex for
-    // performance reasons. 
+    // performance reasons.
     private static boolean shouldInstallMultiDex(Context context) {
         try {
             Method isIsolatedMethod =
@@ -99,7 +99,7 @@ public class ChromiumMultiDex {
 
         String currentProcessName = getProcessName(context);
         if (currentProcessName == null) return true;
-        
+
         PackageManager packageManager = context.getPackageManager();
         try {
             ApplicationInfo appInfo = packageManager.getApplicationInfo(context.getPackageName(),
@@ -110,9 +110,5 @@ public class ChromiumMultiDex {
             return true;
         }
     }
-#else
-    public static void install(Context context) {
-    }
-#endif
 
 }