bluetooth: Allow variable test scan duration

This change enables the scan duration to be set for a test. This
enables tests to have the ability to manipulate events during a scan.
The purpose for this change is to implement a scanning API for Web
Bluetooth Tests. The design for this API is found in the following
document:
https://docs.google.com/document/d/1XFl_4ZAgO8ddM6U53A9AfUuZeWgJnlYD5wtbXqEpzeg

BUG=719826

Change-Id: I6e060ee8d4d149134331c983a9cb884d9ae557f5
Reviewed-on: https://chromium-review.googlesource.com/930123
Commit-Queue: Ovidio Henriquez <odejesush@chromium.org>
Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: Conley Owens <cco3@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540287}

content/browser/bluetooth/bluetooth_device_chooser_controller.cc

@@ -81,17 +81,14 @@ const int k80thPercentileRSSI = -52;
 
 namespace content {
 
-bool BluetoothDeviceChooserController::use_test_scan_duration_ = false;
+// Sets the default duration for a Bluetooth scan to 60 seconds.
+int64_t BluetoothDeviceChooserController::scan_duration_ = 60;
 
 namespace {
 // Max length of device name in filter. Bluetooth 5.0 3.C.3.2.2.3 states that
 // the maximum device name length is 248 bytes (UTF-8 encoded).
 constexpr size_t kMaxLengthForDeviceName = 248;
 
-// The duration of a Bluetooth Scan in seconds.
-constexpr int kScanDuration = 60;
-constexpr int kTestScanDuration = 0;
-
 void LogRequestDeviceOptions(
     const blink::mojom::WebBluetoothRequestDeviceOptionsPtr& options) {
   DVLOG(1) << "requestDevice called with the following filters: ";
@@ -281,10 +278,7 @@ BluetoothDeviceChooserController::BluetoothDeviceChooserController(
       web_contents_(WebContents::FromRenderFrameHost(render_frame_host_)),
       discovery_session_timer_(
           FROM_HERE,
-          // TODO(jyasskin): Add a way for tests to control the dialog
-          // directly, and change this to a reasonable discovery timeout.
-          base::TimeDelta::FromSeconds(
-              use_test_scan_duration_ ? kTestScanDuration : kScanDuration),
+          base::TimeDelta::FromSeconds(scan_duration_),
           base::Bind(&BluetoothDeviceChooserController::StopDeviceDiscovery,
                      // base::Timer guarantees it won't call back after its
                      // destructor starts.
@@ -490,8 +484,16 @@ int BluetoothDeviceChooserController::CalculateSignalStrengthLevel(
   }
 }
 
-void BluetoothDeviceChooserController::SetTestScanDurationForTesting() {
-  BluetoothDeviceChooserController::use_test_scan_duration_ = true;
+void BluetoothDeviceChooserController::SetTestScanDurationForTesting(
+    TestScanDurationSetting setting) {
+  switch (setting) {
+    case TestScanDurationSetting::IMMEDIATE_TIMEOUT:
+      scan_duration_ = 0;
+      break;
+    case TestScanDurationSetting::NEVER_TIMEOUT:
+      scan_duration_ = base::TimeDelta::Max().InSeconds();
+      break;
+  }
 }
 
 void BluetoothDeviceChooserController::PopulateConnectedDevices() {

content/browser/bluetooth/bluetooth_device_chooser_controller.h

@@ -39,6 +39,8 @@ class CONTENT_EXPORT BluetoothDeviceChooserController final {
   typedef base::Callback<void(blink::mojom::WebBluetoothResult result)>
       ErrorCallback;
 
+  enum class TestScanDurationSetting { IMMEDIATE_TIMEOUT, NEVER_TIMEOUT };
+
   // |web_bluetooth_service_| service that owns this class.
   // |render_frame_host| should be the RenderFrameHost that owns the
   // |web_bluetooth_service_|.
@@ -83,9 +85,14 @@ class CONTENT_EXPORT BluetoothDeviceChooserController final {
   // present in a received radio signal.
   static int CalculateSignalStrengthLevel(int8_t rssi);
 
-  // After this method is called any new instance of
-  // BluetoothDeviceChooserController will have a scan duration of 0.
-  static void SetTestScanDurationForTesting();
+  // After this method is called, any new instance of
+  // BluetoothDeviceChooserController will have a scan duration determined by
+  // the |setting| enum. The possible enumerations are described below:
+  //   IMMEDIATE_TIMEOUT: Sets the scan duration to 0 seconds.
+  //   NEVER_TIMEOUT:     Sets the scan duration to INT_MAX seconds.
+  static void SetTestScanDurationForTesting(
+      TestScanDurationSetting setting =
+          TestScanDurationSetting::IMMEDIATE_TIMEOUT);
 
  private:
   // Populates the chooser with the GATT connected devices.
@@ -115,8 +122,9 @@ class CONTENT_EXPORT BluetoothDeviceChooserController final {
   // Helper function to asynchronously run error_callback_.
   void PostErrorCallback(blink::mojom::WebBluetoothResult result);
 
-  // If true all new instances of this class will have a scan duration of 0.
-  static bool use_test_scan_duration_;
+  // Stores the scan duration to use for the discovery session timer.
+  // The default value is 60 seconds.
+  static int64_t scan_duration_;
 
   // The adapter used to get existing devices and start a discovery session.
   device::BluetoothAdapter* adapter_;