[android_webview] Add a generic callback JNI bridge.

android_webview/native/webview_native.gyp

Index: android_webview/native/webview_native.gyp
diff --git a/android_webview/native/webview_native.gyp b/android_webview/native/webview_native.gyp
index cb9562a69c5016e3049cda533606230da0d68563..aa29ca688fbe590ce6589c1c95bcdd27012c22b8 100644
--- a/android_webview/native/webview_native.gyp
+++ b/android_webview/native/webview_native.gyp
@@ -45,6 +45,8 @@
         'aw_web_contents_delegate.h',
         'aw_web_contents_view_delegate.cc',
         'aw_web_contents_view_delegate.h',
+        'callback_jni_bridge.cc',
+        'callback_jni_bridge.h',
         'cookie_manager.cc',
         'cookie_manager.h',
         'input_stream_impl.cc',
@@ -61,7 +63,7 @@
       ],
     },
     {
-      'target_name': 'android_jar_jni_headers',
+      'target_name': 'input_stream_jni_headers',
       'type': 'none',
       'variables': {
         'jni_gen_dir': 'android_webview',
@@ -82,6 +84,7 @@
           '../java/src/org/chromium/android_webview/AwResource.java',
           '../java/src/org/chromium/android_webview/AwSettings.java',
           '../java/src/org/chromium/android_webview/AwWebContentsDelegate.java',
+          '../java/src/org/chromium/android_webview/CallbackJNIBridge.java',
           '../java/src/org/chromium/android_webview/InterceptedRequestData.java',
           '../java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java',
           '../java/src/org/chromium/android_webview/JsResultHandler.java',
@@ -91,7 +94,7 @@
       },
       'includes': [ '../../build/jni_generator.gypi' ],
       'dependencies': [
-        'android_jar_jni_headers',
+        'input_stream_jni_headers',
       ],
     },
   ],