Android: Add a java version of ObserverList.

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index 33c334d6b54f4c2cd03b785ed1c75453f685fb8c..2ec7c00a236908d294427ee2eb5ea7bb6b296824 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -1118,6 +1118,9 @@
         {
           'target_name': 'base_java',
           'type': 'none',
+          'dependencies': [
+            '../third_party/jsr-305/jsr-305.gyp:jsr_305_javalib',
+          ],
           'variables': {
             'java_in_dir': '../base/android/java',
           },
@@ -1134,6 +1137,18 @@
           },
           'includes': [ '../build/java.gypi' ],
         },
+        {
+          'target_name': 'base_javatests',
+          'type': 'none',
+          'dependencies': [
+            'base_java',
+            'base_java_test_support',
+          ],
+          'variables': {
+            'java_in_dir': '../base/android/javatests',
+          },
+          'includes': [ '../build/java.gypi' ],
+        },
       ],
     }],
     ['OS == "win"', {