Mac Video Capture: correct to float the erroneous handling of frame rate as int.

media/video/capture/mac/video_capture_device_avfoundation_mac.h

 // Copyright 2013 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 MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_AVFOUNDATION_MAC_H_
 #define MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_AVFOUNDATION_MAC_H_
 
 #import <Foundation/Foundation.h>
 
 #import "base/mac/scoped_nsobject.h"
@@ skipping 44 matching lines @@
 //    the VideoCaptureDeviceAVFoundation object.
 //
 //
 @interface VideoCaptureDeviceAVFoundation
     : NSObject<CrAVCaptureVideoDataOutputSampleBufferDelegate,
                PlatformVideoCapturingMac> {
  @private
   // The following attributes are set via -setCaptureHeight:width:frameRate:.
   int frameWidth_;
   int frameHeight_;
-  int frameRate_;
+  float frameRate_;
 
   base::Lock lock_;  // Protects concurrent setting and using of frameReceiver_.
   media::VideoCaptureDeviceMac* frameReceiver_;  // weak.
 
   base::scoped_nsobject<CrAVCaptureSession> captureSession_;
 
   // |captureDevice_| is an object coming from AVFoundation, used only to be
   // plugged in |captureDeviceInput_| and to query for session preset support.
   CrAVCaptureDevice* captureDevice_;
   // |captureDeviceInput_| is owned by |captureSession_|.
@@ skipping 22 matching lines @@
 // the deviceId is known, the library objects are created if needed and
 // connected for the capture, and a by default resolution is set. If deviceId is
 // nil, then the eventual capture is stopped and library objects are
 // disconnected. Returns YES on sucess, NO otherwise. This method should not be
 // called during capture.
 - (BOOL)setCaptureDevice:(NSString*)deviceId;
 
 // Configures the capture properties for the capture session and the video data
 // output; this means it MUST be called after setCaptureDevice:. Return YES on
 // success, else NO.
-- (BOOL)setCaptureHeight:(int)height width:(int)width frameRate:(int)frameRate;
+- (BOOL)setCaptureHeight:(int)height
+                   width:(int)width
+               frameRate:(float)frameRate;
 
 // Starts video capturing and register the notification listeners. Must be
 // called after setCaptureDevice:, and, eventually, also after
 // setCaptureHeight:width:frameRate:. Returns YES on sucess, NO otherwise.
 - (BOOL)startCapture;
 
 // Stops video capturing and stops listening to notifications.
 - (void)stopCapture;
 
 @end
 
 #endif  // MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_AVFOUNDATION_MAC_H_