Stop providing Physical Web metadata after Bluetooth is disabled

ios/chrome/common/physical_web/physical_web_scanner.mm

 // 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.
 
 #import "ios/chrome/common/physical_web/physical_web_scanner.h"
 
 #import <CoreBluetooth/CoreBluetooth.h>
 
 #include <string>
 #include <vector>
@@ skipping 142 matching lines @@
     return;
   for (PhysicalWebRequest* request in pendingRequests_.get()) {
     [request cancel];
   }
   [pendingRequests_ removeAllObjects];
   if (!pendingStart_ && [self bluetoothEnabled]) {
     [self reallyStop];
   }
   pendingStart_ = NO;
   started_ = NO;
+  if (onLostDetectionEnabled_ && [devices_ count]) {
+    [delegate_ scannerUpdatedDevices:self];
+  }
 }
 
 - (NSArray*)devices {
+  if (![self bluetoothEnabled]) {
+    return [NSArray array];
+  }
   return [devices_ sortedArrayUsingComparator:^(id obj1, id obj2) {
     PhysicalWebDevice* device1 = obj1;
     PhysicalWebDevice* device2 = obj2;
     // Sorts in ascending order.
     if ([device1 rank] > [device2 rank]) {
       return NSOrderedDescending;
     }
     if ([device1 rank] < [device2 rank]) {
       return NSOrderedAscending;
     }
@@ skipping 82 matching lines @@
         [[NSTimer scheduledTimerWithTimeInterval:kUpdateIntervalSeconds
                                           target:self
                                         selector:@selector(onUpdateTimeElapsed:)
                                         userInfo:nil
                                          repeats:YES] retain]);
   }
   [centralManager_ scanForPeripheralsWithServices:serviceUUIDs options:nil];
 }
 
 - (void)reallyStop {
-  if (updateTimer_.get()) {
-    [updateTimer_ invalidate];
-    updateTimer_.reset();
-  }
-
   [centralManager_ stopScan];
 }
 
 - (void)onUpdateTimeElapsed:(NSTimer*)timer {
   NSDate* now = [NSDate date];
   NSMutableArray* lostDevices = [NSMutableArray array];
   NSMutableArray* lostUnresolvedDevices = [NSMutableArray array];
   NSMutableArray* lostScannedUrls = [NSMutableArray array];
 
   for (PhysicalWebDevice* device in devices_.get()) {
@@ skipping 30 matching lines @@
   [pendingRequests_ removeObjectsInArray:requestsToRemove];
 
   if ([lostDevices count]) {
     [delegate_ scannerUpdatedDevices:self];
   }
 
   // TODO(crbug.com/657056): Remove this workaround when radar is fixed.
   // For unknown reasons, when scanning for longer periods (on the order of
   // minutes), the scanner is less reliable at detecting all nearby URLs. As a
   // workaround, we restart the scanner each time we check for lost URLs.
-  NSArray* serviceUUIDs = @[
-    [CBUUID UUIDWithString:kUriBeaconServiceUUID],
-    [CBUUID UUIDWithString:kEddystoneBeaconServiceUUID]
-  ];
-  [centralManager_ stopScan];
-  [centralManager_ scanForPeripheralsWithServices:serviceUUIDs options:nil];
+  if (!pendingStart_) {
+    NSArray* serviceUUIDs = @[
+      [CBUUID UUIDWithString:kUriBeaconServiceUUID],
+      [CBUUID UUIDWithString:kEddystoneBeaconServiceUUID]
+    ];
+    [centralManager_ stopScan];
+    [centralManager_ scanForPeripheralsWithServices:serviceUUIDs options:nil];
+  }
+
+  if (updateTimer_.get() && pendingStart_ && [devices_ count] == 0) {
+    [updateTimer_ invalidate];
+    updateTimer_.reset();
+  }
 }
 
 #pragma mark -
 #pragma mark CBCentralManagerDelegate methods
 
 - (void)centralManagerDidUpdateState:(CBCentralManager*)central {
   if ([self bluetoothEnabled]) {
     if (pendingStart_)
       [self reallyStart];
   } else {
     if (started_ && !pendingStart_) {
       pendingStart_ = YES;
-      [self reallyStop];

[mattreynolds, 2016/11/18 00:03:25]

This was a bug, calling [centralManager_ stopScan] with Bluetooth disabled is an
error and generates an API MISUSE log message.

     }
   }
   [delegate_ scannerBluetoothStatusUpdated:self];
 }
 
 + (BeaconType)beaconTypeForAdvertisementData:(NSDictionary*)advertisementData {
   NSDictionary* serviceData =
       [advertisementData objectForKey:CBAdvertisementDataServiceDataKey];
   if ([serviceData objectForKey:[CBUUID UUIDWithString:kUriBeaconServiceUUID]])
     return BEACON_TYPE_URIBEACON;
@@ skipping 132 matching lines @@
         [strongSelf.get()->devices_ addObject:device];
         [strongSelf.get()->delegate_ scannerUpdatedDevices:weakSelf];
         [strongSelf.get()->finalUrls_ addObject:[device url]];
       }
     }
     [strongSelf.get()->pendingRequests_ removeObject:strongRequest];
   }];
 }
 
 @end