References Search: Add extension which looks for constructor usages in delegation calls

idea/src/META-INF/plugin.xml

@@ -448,6 +448,7 @@
     <definitionsScopedSearch implementation="org.jetbrains.kotlin.idea.search.ideaExtensions.KotlinDefinitionsSearcher"/>
     <annotatedElementsSearch implementation="org.jetbrains.kotlin.idea.search.ideaExtensions.KotlinAnnotatedElementsSearcher"/>
     <methodReferencesSearch implementation="org.jetbrains.kotlin.idea.search.ideaExtensions.KotlinLightPropertyAccessorsReferenceSearcher"/>
+    <methodReferencesSearch implementation="org.jetbrains.kotlin.idea.search.ideaExtensions.KotlinConstructorDelegationCallReferenceSearcher"/>
 
     <exceptionFilter implementation="org.jetbrains.kotlin.idea.filters.JetExceptionFilterFactory" order="first"/>
 

idea/src/org/jetbrains/kotlin/idea/search/ideaExtensions/KotlinConstructorDelegationCallReferenceSearcher.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.search.ideaExtensions
+
+import com.intellij.openapi.application.QueryExecutorBase
+import com.intellij.psi.PsiReference
+import com.intellij.psi.search.searches.MethodReferencesSearch.SearchParameters
+import com.intellij.util.Processor
+import org.jetbrains.kotlin.idea.search.usagesSearch.processDelegationCallConstructorUsages
+
+public class KotlinConstructorDelegationCallReferenceSearcher() : QueryExecutorBase<PsiReference, SearchParameters>(true) {
+    override fun processQuery(queryParameters: SearchParameters, consumer: Processor<PsiReference>) {
+        val method = queryParameters.getMethod()
+        if (!method.isConstructor()) return
+
+        method.processDelegationCallConstructorUsages(method.getUseScope()) {
+            it.getCalleeExpression()?.getReference()?.let { consumer.process(it) }
+        }
+    }
+}