Use Maps#newHashMapWithExpectedSize rather than improper HashMap ctor usage.

RELNOTES: None
PiperOrigin-RevId: 164884056
diff --git a/src/main/java/com/google/devtools/build/lib/query2/SkyQueryEnvironment.java b/src/main/java/com/google/devtools/build/lib/query2/SkyQueryEnvironment.java
index f68fb30..84313ae 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/SkyQueryEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/SkyQueryEnvironment.java
@@ -479,7 +479,7 @@
   @Override
   public ThreadSafeMutableSet<Target> getFwdDeps(Iterable<Target> targets)
       throws InterruptedException {
-    Map<SkyKey, Target> targetsByKey = new HashMap<>(Iterables.size(targets));
+    Map<SkyKey, Target> targetsByKey = Maps.newHashMapWithExpectedSize(Iterables.size(targets));
     for (Target target : targets) {
       targetsByKey.put(TARGET_TO_SKY_KEY.apply(target), target);
     }