Upstream Chrome on iOS source code [1/11].

ios/chrome/app/application_delegate/metrics_mediator.h

+// Copyright 2016 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 IOS_CHROME_APP_APPLICATION_DELEGATE_METRICS_MEDIATOR_H_
+#define IOS_CHROME_APP_APPLICATION_DELEGATE_METRICS_MEDIATOR_H_
+
+#import <UIKit/UIKit.h>
+
+@protocol StartupInformation;
+
+@protocol BrowserViewInformation;
+@protocol StartupInformation;
+
+namespace metrics_mediator {
+// Key in the UserDefaults to store the date/time that the background fetch
+// handler was called.
+extern NSString* const kAppEnteredBackgroundDateKey;
+}  // namespace metrics_mediator
+
+// Deals with metrics, checking and updating them accordingly to to the user
+// preferences.
+@interface MetricsMediator : NSObject
+// Returns YES if the metrics pref is enabled.  Does not take into account the
+// wifi-only option or wwan state.
+- (BOOL)areMetricsEnabled;
+// Return YES if uploading is allowed, based on user preferences.
+- (BOOL)isUploadingEnabled;
+// Starts or stops the metrics service and crash report recording and/or
+// uploading, based on the current user preferences. Makes sure helper
+// mechanisms and the wwan state observer are set up if necessary. Called both
+// on initialization and after user triggered preference change.
+// |isUserTriggered| is used to distinguish between those cases.
+- (void)updateMetricsStateBasedOnPrefsUserTriggered:(BOOL)isUserTriggered;
+// Logs the duration of the cold start startup. Does nothing if there isn't a
+// cold start.
++ (void)logStartupDuration:(id<StartupInformation>)startupInformation;
+// Logs the number of tabs open and the start type.
++ (void)logLaunchMetricsWithStartupInformation:
+            (id<StartupInformation>)startupInformation
+                        browserViewInformation:
+                            (id<BrowserViewInformation>)browserViewInformation;
+// Logs in UserDefaults the current date with kAppEnteredBackgroundDateKey as
+// key.
++ (void)logDateInUserDefaults;
+// Disables reporting in breakpad and metrics service.
++ (void)disableReporting;
+// Logs that the application is in background and the number of memory warnings
+// for this session.
++ (void)applicationDidEnterBackground:(NSInteger)memoryWarningCount;
+
+@end
+
+#endif  // IOS_CHROME_APP_APPLICATION_DELEGATE_METRICS_MEDIATOR_H_