Set the javac target and source to 1.7

base/android/java/src/org/chromium/base/CollectionUtil.java

Index: base/android/java/src/org/chromium/base/CollectionUtil.java
diff --git a/base/android/java/src/org/chromium/base/CollectionUtil.java b/base/android/java/src/org/chromium/base/CollectionUtil.java
index 7e7e0c91c8d5c4da61fd66db8535b875d4397b75..4a4c7540a58cb3f412e7cf6a27abaf10c14b75bf 100644
--- a/base/android/java/src/org/chromium/base/CollectionUtil.java
+++ b/base/android/java/src/org/chromium/base/CollectionUtil.java
@@ -17,12 +17,14 @@ import java.util.HashSet;
 public final class CollectionUtil {
     private CollectionUtil() {}
 
+    @SafeVarargs
     public static <E> HashSet<E> newHashSet(E... elements) {
         HashSet<E> set = new HashSet<E>(elements.length);
         Collections.addAll(set, elements);
         return set;
     }
 
+    @SafeVarargs
     public static <E> ArrayList<E> newArrayList(E... elements) {
         ArrayList<E> list = new ArrayList<E>(elements.length);
         Collections.addAll(list, elements);