Change source look-up design

plugins/org.chromium.debug.core/src/org/chromium/debug/core/util/ChromiumDebugPluginUtil.java

Index: plugins/org.chromium.debug.core/src/org/chromium/debug/core/util/ChromiumDebugPluginUtil.java
diff --git a/plugins/org.chromium.debug.core/src/org/chromium/debug/core/util/ChromiumDebugPluginUtil.java b/plugins/org.chromium.debug.core/src/org/chromium/debug/core/util/ChromiumDebugPluginUtil.java
index 1a49b91b958cb625fc0fa00d4f796df4553c1e91..a14ee4e7d01d8385f1ce6c7d1b123fd15bd1a9f1 100644
--- a/plugins/org.chromium.debug.core/src/org/chromium/debug/core/util/ChromiumDebugPluginUtil.java
+++ b/plugins/org.chromium.debug.core/src/org/chromium/debug/core/util/ChromiumDebugPluginUtil.java
@@ -366,6 +366,22 @@ public class ChromiumDebugPluginUtil {
     return collection.remove(value);
   }
 
+  public static <T> boolean eq(T left, T right) {
+    if (left == null) {
+      return right == null;
+    } else {
+      return left.equals(right);
+    }
+  }
+
+  public static int hashCode(Object obj) {
+    if (obj == null) {
+      return 0;
+    } else {
+      return obj.hashCode();
+    }
+  }
+
   public static String getStacktraceString(Exception exception) {
     StringWriter stringWriter = new StringWriter();
     PrintWriter printWriter = new PrintWriter(stringWriter);