Upstream VariationsSession

BUG=428904

Review URL: https://codereview.chromium.org/1024993003

Cr-Commit-Position: refs/heads/master@{#321891}

chrome/android/java/src/org/chromium/chrome/browser/metrics/VariationsSession.java

+// 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.
+
+package org.chromium.chrome.browser.metrics;
+
+import android.content.Context;
+
+/**
+ * Sets up communication with the VariationsService. This is primarily used for
+ * triggering seed fetches on application startup.
+ */
+public class VariationsSession {
+    private boolean mInitialized;
+    private String mRestrictMode;
+
+    /**
+     * Triggers to the native VariationsService that the application has entered the foreground.
+     */
+    public void start(Context context) {
+        if (!mInitialized) {
+            mInitialized = true;
+            // Check the restrict mode only once initially to avoid doing extra work each time the
+            // app enters foreground.
+            mRestrictMode = getRestrictMode(context);
+        }
+        nativeStartVariationsSession(mRestrictMode);
+    }
+
+    /**
+     * Returns the value of the "restrict" URL param that the variations service should use for
+     * variation seed requests.
+     */
+    protected String getRestrictMode(Context context) {
+        return "";
+    }
+
+    private native void nativeStartVariationsSession(String restrictMode);
+}

chrome/browser/android/chrome_jni_registrar.cc

@@ -37,6 +37,7 @@
 #include "chrome/browser/android/metrics/uma_bridge.h"
 #include "chrome/browser/android/metrics/uma_session_stats.h"
 #include "chrome/browser/android/metrics/uma_utils.h"
+#include "chrome/browser/android/metrics/variations_session.h"
 #include "chrome/browser/android/most_visited_sites.h"
 #include "chrome/browser/android/new_tab_page_prefs.h"
 #include "chrome/browser/android/omnibox/answers_image_bridge.h"
@@ -248,6 +249,7 @@ static base::android::RegistrationMethod kChromeRegisteredMethods[] = {
     {"UmaSessionStats", RegisterUmaSessionStats},
     {"UrlUtilities", RegisterUrlUtilities},
     {"Variations", variations::android::RegisterVariations},
+    {"VariationsSession", chrome::android::RegisterVariationsSession},
     {"WarmupManager", RegisterWarmupManager},
     {"WebsitePreferenceBridge", RegisterWebsitePreferenceBridge},
     {"WebsiteSettingsPopupAndroid",

chrome/browser/android/metrics/variations_session.cc

+// 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/metrics/variations_session.h"
+
+#include "base/android/jni_string.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/metrics/variations/variations_service.h"
+#include "jni/VariationsSession_jni.h"
+
+namespace {
+
+// Tracks whether VariationsService::OnAppEnterForeground() has been called
+// previously, in order to set the restrict mode param before the first call.
+bool g_on_app_enter_foreground_called = false;
+
+}  // namespace
+
+static void StartVariationsSession(JNIEnv* env,
+                                   jobject obj,
+                                   jstring jrestrict_mode) {
+  DCHECK(g_browser_process);
+
+  chrome_variations::VariationsService* variations_service =
+      g_browser_process->variations_service();
+  // Triggers an OnAppEnterForeground on the VariationsService. This may fetch
+  // a new seed.
+  if (variations_service) {
+    std::string restrict_mode =
+        base::android::ConvertJavaStringToUTF8(env, jrestrict_mode);
+    if (!restrict_mode.empty() && !g_on_app_enter_foreground_called)
+      variations_service->SetRestrictMode(restrict_mode);
+    variations_service->OnAppEnterForeground();
+    g_on_app_enter_foreground_called = true;
+  }
+}
+
+namespace chrome {
+namespace android {
+
+// Register native methods
+bool RegisterVariationsSession(JNIEnv* env) { return RegisterNativesImpl(env); }
+
+}  // namespace android
+}  // namespace chrome

chrome/browser/android/metrics/variations_session.h

+// 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_METRICS_VARIATIONS_SESSION_H_
+#define CHROME_BROWSER_ANDROID_METRICS_VARIATIONS_SESSION_H_
+
+#include <jni.h>
+
+namespace chrome {
+namespace android {
+
+// Registers the native methods through jni.
+bool RegisterVariationsSession(JNIEnv* env);
+
+}  // namespace android
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_ANDROID_METRICS_VARIATIONS_SESSION_H_

chrome/chrome_browser.gypi

@@ -117,6 +117,8 @@
       'browser/android/metrics/uma_session_stats.h',
       'browser/android/metrics/uma_utils.cc',
       'browser/android/metrics/uma_utils.h',
+      'browser/android/metrics/variations_session.cc',
+      'browser/android/metrics/variations_session.h',
       'browser/android/most_visited_sites.cc',
       'browser/android/most_visited_sites.h',
       'browser/android/new_tab_page_prefs.cc',
@@ -1638,6 +1640,7 @@
       'android/java/src/org/chromium/chrome/browser/metrics/UmaBridge.java',
       'android/java/src/org/chromium/chrome/browser/metrics/UmaSessionStats.java',
       'android/java/src/org/chromium/chrome/browser/metrics/UmaUtils.java',
+      'android/java/src/org/chromium/chrome/browser/metrics/VariationsSession.java',
       'android/java/src/org/chromium/chrome/browser/NavigationPopup.java',
       'android/java/src/org/chromium/chrome/browser/net/spdyproxy/DataReductionProxySettings.java',
       'android/java/src/org/chromium/chrome/browser/infobar/DownloadOverwriteInfoBar.java',