Create a Java SessionTabHelper

Create a Java SessionTabHelper with idForTab so that the
DataUseTabUIManager in Java can get the C++ notion of a tab ID from
a Java tab.

TBR=thestig@chromium.org

BUG=547256

Review URL: https://codereview.chromium.org/1423933002

Cr-Commit-Position: refs/heads/master@{#357462}

2 files changed, 37 insertions, 0 deletions

diff --git a/chrome/browser/android/sessions/session_tab_helper_android.cc b/chrome/browser/android/sessions/session_tab_helper_android.cc
new file mode 100644
index 0000000..7411543
--- /dev/null
+++ b/chrome/browser/android/sessions/session_tab_helper_android.cc
@@ -0,0 +1,24 @@
+// Copyright 2015 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.
+
+#include "chrome/browser/android/sessions/session_tab_helper_android.h"
+
+#include "base/android/jni_android.h"
+#include "chrome/browser/sessions/session_tab_helper.h"
+#include "content/public/browser/web_contents.h"
+#include "jni/SessionTabHelper_jni.h"
+
+// static
+jint IdForTab(JNIEnv* env,
+              const JavaParamRef<jclass>& clazz,
+              const JavaParamRef<jobject>& java_web_contents) {
+  content::WebContents* web_contents =
+      content::WebContents::FromJavaWebContents(java_web_contents);
+  CHECK(web_contents);
+  return SessionTabHelper::IdForTab(web_contents);
+}
+
+bool RegisterSessionTabHelper(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
diff --git a/chrome/browser/android/sessions/session_tab_helper_android.h b/chrome/browser/android/sessions/session_tab_helper_android.h
new file mode 100644
index 0000000..e73fa71
--- /dev/null
+++ b/chrome/browser/android/sessions/session_tab_helper_android.h
@@ -0,0 +1,13 @@
+// Copyright 2015 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_ANDROID_SESSIONS_SESSION_TAB_HELPER_ANDROID_H_
+#define CHROME_BROWSER_ANDROID_SESSIONS_SESSION_TAB_HELPER_ANDROID_H_
+
+#include <jni.h>
+
+// Registers the SessionTabHelper's native methods through JNI.
+bool RegisterSessionTabHelper(JNIEnv* env);
+
+#endif  // CHROME_BROWSER_ANDROID_SESSIONS_SESSION_TAB_HELPER_ANDROID_H_