Add Android support for SSL client authentication to the browser layer.

chrome/browser/ui/android/ssl_client_certificate_request_jni.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_ANDROID_SSL_CLIENT_CERTIFICATE_REQUEST_JNI_H_
+#define CHROME_BROWSER_UI_ANDROID_SSL_CLIENT_CERTIFICATE_REQUEST_JNI_H_
+
+#include <jni.h>
+
+// Register JNI methods for SSLClientCertificateRequest.java
+// This is implemented by ssl_client_certificate_request.cc but
+// appears in an independent header to avoid dragging OpenSSL include
+// path dependencies into chrome_browser.gypi.

[bulach, 2013/02/28 16:34:18]

sorry, I'm not quite sure I understood this... would you have any error message?
I think it's doable to just add this a function in
ssl_client_certificate_request.h, or maybe even more scoped, a static function
in SSLClientCertificateRequest itself?

it seems that the ssl_client_certificate_request.h provides all forward
declaration necessary to that the generated JNI code can bind everything
correctly, fairly similar to content_view_core_impl.cc and many other classes,
no?
let me know what is broken, I'll be glad to fix it!

[digit, 2013/02/28 16:49:00]

Yes, I know it's a bit confusing.
So this function is used only in chrome/browser/android/chrome_jni_registrar.cc.

In a previous version of this patch, this declaration was in
ssl_client_certificate_request.h, which was included by chrome_jni_registrar.cc.

But that header includes OpenSSL-specific headers, which themselves have to
include OpenSSL headers (e.g. <openssl/evp.h>). And this is a requirement of
using scoped ref-counted OpenSSL types in the class definition.

chrome_jni_registrar.cc would not compile unless I add openssl as a
Android-specific dependency to the 'browser' target in chrome_browser.gypi.

Note that openssl is already a dependency for the 'browser_ui' target, which
doesn't seem to have its own JNI registration stuff.

By placing the declaration here, I avoid this problem entirely, but if you have
a better solution, or you just think that 'browser' should depend on OpenSSL,
just let me know.

[digit1, 2013/03/04 19:03:20]

I've reworked the code to get rid of this header.
Now, SSLClientCertificateRequest is now a simpler base class, and the
RegisterXXX function can be placed in ssl_client_certificate_request.h properly.

ssl_client_cetificate_selector_android.cc provides a subclass that extends it
with the necessary missing bits. The end result is also a bit cleaner, i.e.
SSLClientCertiicateRequest only deals with JNI calls and objects, while the
subclass deals with the tricky thread ping-pong and callback calls.

+bool RegisterSSLClientCertificateRequestAndroid(JNIEnv* env);
+
+#endif  // CHROME_BROWSER_UI_ANDROID_SSL_CLIENT_CERTIFICATE_REQUEST_JNI_H_