Change the functions in video_capture_device to pass around PowerLineFrequency enums instead of integers to reduce the amount of static casting required

BUG=525167

Review URL: https://codereview.chromium.org/1345993002

Cr-Commit-Position: refs/heads/master@{#352234}

6 files changed, 31 insertions, 30 deletions

diff --git a/media/capture/video/linux/video_capture_device_linux.cc b/media/capture/video/linux/video_capture_device_linux.cc
index 487199e..cbf2b49 100644
--- a/media/capture/video/linux/video_capture_device_linux.cc
+++ b/media/capture/video/linux/video_capture_device_linux.cc
@@ -132,11 +132,12 @@ void VideoCaptureDeviceLinux::SetRotation(int rotation) {
 }
 
 // static
-int VideoCaptureDeviceLinux::TranslatePowerLineFrequencyToV4L2(int frequency) {
+int VideoCaptureDeviceLinux::TranslatePowerLineFrequencyToV4L2(
+    PowerLineFrequency frequency) {
   switch (frequency) {
-    case static_cast<int>(media::PowerLineFrequency::FREQUENCY_50HZ):
+    case media::PowerLineFrequency::FREQUENCY_50HZ:
       return V4L2_CID_POWER_LINE_FREQUENCY_50HZ;
-    case static_cast<int>(media::PowerLineFrequency::FREQUENCY_60HZ):
+    case media::PowerLineFrequency::FREQUENCY_60HZ:
       return V4L2_CID_POWER_LINE_FREQUENCY_60HZ;
     default:
       // If we have no idea of the frequency, at least try and set it to AUTO.
diff --git a/media/capture/video/linux/video_capture_device_linux.h b/media/capture/video/linux/video_capture_device_linux.h
index 61e2cba..100d87f 100644
--- a/media/capture/video/linux/video_capture_device_linux.h
+++ b/media/capture/video/linux/video_capture_device_linux.h
@@ -41,7 +41,7 @@ class VideoCaptureDeviceLinux : public VideoCaptureDevice {
   void SetRotation(int rotation);
 
  private:
-  static int TranslatePowerLineFrequencyToV4L2(int frequency);
+  static int TranslatePowerLineFrequencyToV4L2(PowerLineFrequency frequency);
 
   // Internal delegate doing the actual capture setting, buffer allocation and
   // circulation with the V4L2 API. Created and deleted in the thread where
diff --git a/media/capture/video/mac/video_capture_device_mac.mm b/media/capture/video/mac/video_capture_device_mac.mm
index 8f71b68..5fc083e 100644
--- a/media/capture/video/mac/video_capture_device_mac.mm
+++ b/media/capture/video/mac/video_capture_device_mac.mm
@@ -189,7 +189,7 @@ static bool FindVideoControlInterfaceInDeviceInterface(
 // set the appropriate Power Line frequency for flicker removal.
 static void SetAntiFlickerInVideoControlInterface(
     IOCFPlugInInterface** plugin_interface,
-    const int frequency) {
+    const PowerLineFrequency frequency) {
   // Create, the control interface for the found plugin, and release
   // the intermediate plugin.
   IOUSBInterfaceInterface** control_interface = NULL;
@@ -249,7 +249,8 @@ static void SetAntiFlickerInVideoControlInterface(
   command.wValue = (selector << 8);
   command.wLength = kPuPowerLineFrequencyControlCommandSize;
   command.wLenDone = 0;
-  int power_line_flag_value = (frequency == 50) ? k50Hz : k60Hz;
+  int power_line_flag_value =
+      (frequency == PowerLineFrequency::FREQUENCY_50HZ) ? k50Hz : k60Hz;
   command.pData = &power_line_flag_value;
 
   IOReturn ret =
@@ -257,8 +258,8 @@ static void SetAntiFlickerInVideoControlInterface(
   DLOG_IF(ERROR, ret != kIOReturnSuccess) << "Anti-flicker control request"
                                           << " failed (0x" << std::hex << ret
                                           << "), unit id: " << real_unit_id;
-  DVLOG_IF(1, ret == kIOReturnSuccess) << "Anti-flicker set to " << frequency
-                                       << "Hz";
+  DVLOG_IF(1, ret == kIOReturnSuccess) << "Anti-flicker set to "
+                                       << static_cast<int>(frequency) << "Hz";
 
   (*control_interface)->USBInterfaceClose(control_interface);
 }
@@ -270,11 +271,11 @@ static void SetAntiFlickerInVideoControlInterface(
 // are created. The latter is used to a send a power frequency setting command.
 static void SetAntiFlickerInUsbDevice(const int vendor_id,
                                       const int product_id,
-                                      const int frequency) {
-  if (frequency == 0)
+                                      const PowerLineFrequency frequency) {
+  if (frequency == PowerLineFrequency::FREQUENCY_DEFAULT)
     return;
-  DVLOG(1) << "Setting Power Line Frequency to " << frequency << " Hz, device "
-           << std::hex << vendor_id << "-" << product_id;
+  DVLOG(1) << "Setting Power Line Frequency to " << static_cast<int>(frequency)
+           << " Hz, device " << std::hex << vendor_id << "-" << product_id;
 
   // Compose a search dictionary with vendor and product ID.
   CFMutableDictionaryRef query_dictionary =
diff --git a/media/capture/video/video_capture_device.cc b/media/capture/video/video_capture_device.cc
index 01816c2..e7e2c91 100644
--- a/media/capture/video/video_capture_device.cc
+++ b/media/capture/video/video_capture_device.cc
@@ -145,10 +145,11 @@ VideoCaptureDevice::Client::Buffer::~Buffer() {
 VideoCaptureDevice::~VideoCaptureDevice() {
 }
 
-int VideoCaptureDevice::GetPowerLineFrequencyForLocation() const {
-  std::string current_country = base::CountryCodeForCurrentTimezone();
+PowerLineFrequency VideoCaptureDevice::GetPowerLineFrequencyForLocation()
+    const {
+  const std::string current_country = base::CountryCodeForCurrentTimezone();
   if (current_country.empty())
-    return 0;
+    return PowerLineFrequency::FREQUENCY_DEFAULT;
   // Sorted out list of countries with 60Hz power line frequency, from
   // http://en.wikipedia.org/wiki/Mains_electricity_by_country
   const char* countries_using_60Hz[] = {
@@ -160,17 +161,17 @@ int VideoCaptureDevice::GetPowerLineFrequencyForLocation() const {
       countries_using_60Hz + arraysize(countries_using_60Hz);
   if (std::find(countries_using_60Hz, countries_using_60Hz_end,
                 current_country) == countries_using_60Hz_end) {
-    return static_cast<int>(media::PowerLineFrequency::FREQUENCY_50HZ);
+    return media::PowerLineFrequency::FREQUENCY_50HZ;
   }
-  return static_cast<int>(media::PowerLineFrequency::FREQUENCY_60HZ);
+  return media::PowerLineFrequency::FREQUENCY_60HZ;
 }
 
-int VideoCaptureDevice::GetPowerLineFrequency(
+PowerLineFrequency VideoCaptureDevice::GetPowerLineFrequency(
     const VideoCaptureParams& params) const {
   switch (params.power_line_frequency) {
     case media::PowerLineFrequency::FREQUENCY_50HZ:  // fall through
     case media::PowerLineFrequency::FREQUENCY_60HZ:
-      return static_cast<int>(params.power_line_frequency);
+      return params.power_line_frequency;
     default:
       return GetPowerLineFrequencyForLocation();
   }
diff --git a/media/capture/video/video_capture_device.h b/media/capture/video/video_capture_device.h
index 33601336..b66409b 100644
--- a/media/capture/video/video_capture_device.h
+++ b/media/capture/video/video_capture_device.h
@@ -283,12 +283,13 @@ class MEDIA_EXPORT VideoCaptureDevice {
 
   // Gets the power line frequency, either from the params if specified by the
   // user or from the current system time zone.
-  int GetPowerLineFrequency(const VideoCaptureParams& params) const;
+  PowerLineFrequency GetPowerLineFrequency(
+      const VideoCaptureParams& params) const;
 
  private:
   // Gets the power line frequency from the current system time zone if this is
   // defined, otherwise returns 0.
-  int GetPowerLineFrequencyForLocation() const;
+  PowerLineFrequency GetPowerLineFrequencyForLocation() const;
 };
 
 }  // namespace media
diff --git a/media/capture/video/win/video_capture_device_win.cc b/media/capture/video/win/video_capture_device_win.cc
index 055fc21..9960406 100644
--- a/media/capture/video/win/video_capture_device_win.cc
+++ b/media/capture/video/win/video_capture_device_win.cc
@@ -539,11 +539,9 @@ bool VideoCaptureDeviceWin::CreateCapabilityMap() {
 // Set the power line frequency removal in |capture_filter_| if available.
 void VideoCaptureDeviceWin::SetAntiFlickerInCaptureFilter(
     const VideoCaptureParams& params) {
-  const int power_line_frequency = GetPowerLineFrequency(params);
-  if (power_line_frequency !=
-          static_cast<int>(media::PowerLineFrequency::FREQUENCY_50HZ) &&
-      power_line_frequency !=
-          static_cast<int>(media::PowerLineFrequency::FREQUENCY_60HZ)) {
+  const PowerLineFrequency power_line_frequency = GetPowerLineFrequency(params);
+  if (power_line_frequency != media::PowerLineFrequency::FREQUENCY_50HZ &&
+      power_line_frequency != media::PowerLineFrequency::FREQUENCY_60HZ) {
     return;
   }
   ScopedComPtr<IKsPropertySet> ks_propset;
@@ -559,10 +557,9 @@ void VideoCaptureDeviceWin::SetAntiFlickerInCaptureFilter(
     data.Property.Set = PROPSETID_VIDCAP_VIDEOPROCAMP;
     data.Property.Id = KSPROPERTY_VIDEOPROCAMP_POWERLINE_FREQUENCY;
     data.Property.Flags = KSPROPERTY_TYPE_SET;
-    data.Value = (power_line_frequency ==
-                  static_cast<int>(media::PowerLineFrequency::FREQUENCY_50HZ))
-                     ? 1
-                     : 2;
+    data.Value =
+        (power_line_frequency == media::PowerLineFrequency::FREQUENCY_50HZ) ? 1
+                                                                            : 2;
     data.Flags = KSPROPERTY_VIDEOPROCAMP_FLAGS_MANUAL;
     hr = ks_propset->Set(PROPSETID_VIDCAP_VIDEOPROCAMP,
                          KSPROPERTY_VIDEOPROCAMP_POWERLINE_FREQUENCY, &data,