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

media/video/capture/mac/video_capture_device_qtkit_mac.mm

 // Copyright (c) 2012 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 "media/video/capture/mac/video_capture_device_qtkit_mac.h"
 
 #import <QTKit/QTKit.h>
 
 #include "base/debug/crash_logging.h"
 #include "base/logging.h"
@@ skipping 156 matching lines @@
                                      waitUntilDone:YES];
     }
     [captureSession_ release];
     captureSession_ = nil;
     [captureDeviceInput_ release];
     captureDeviceInput_ = nil;
     return YES;
   }
 }
 
-- (BOOL)setCaptureHeight:(int)height width:(int)width frameRate:(int)frameRate {
+- (BOOL)setCaptureHeight:(int)height
+                   width:(int)width
+               frameRate:(float)frameRate {
   if (!captureDeviceInput_) {
     [self sendErrorString:[NSString
         stringWithUTF8String:"No video capture device set."]];
     return NO;
   }
   if ([[captureSession_ outputs] count] != 1) {
     [self sendErrorString:[NSString
         stringWithUTF8String:"Video capture capabilities already set."]];
     return NO;
   }
-  if (frameRate <= 0) {
+  if (frameRate <= 0.0f) {
     [self sendErrorString:[NSString stringWithUTF8String: "Wrong frame rate."]];
     return NO;
   }
 
   frameRate_ = frameRate;
 
   QTCaptureDecompressedVideoOutput *output =
       [[captureSession_ outputs] objectAtIndex:0];
 
   // Set up desired output properties. The old capture dictionary is used to
   // retrieve the initial pixel format, which must be maintained.
   NSDictionary* videoSettingsDictionary = @{
     (id)kCVPixelBufferWidthKey : @(width),
     (id)kCVPixelBufferHeightKey : @(height),
     (id)kCVPixelBufferPixelFormatTypeKey : [[output pixelBufferAttributes]
         valueForKey:(id)kCVPixelBufferPixelFormatTypeKey]
   };
   [output setPixelBufferAttributes:videoSettingsDictionary];
 
-  [output setMinimumVideoFrameInterval:(NSTimeInterval)1/(float)frameRate];
+  [output setMinimumVideoFrameInterval:(NSTimeInterval)1/frameRate];
   return YES;
 }
 
 - (BOOL)startCapture {
   if ([[captureSession_ outputs] count] == 0) {
     // Capture properties not set.
     [self sendErrorString:[NSString
         stringWithUTF8String:"Video capture device not initialized."]];
     return NO;
   }
@@ skipping 118 matching lines @@
 
 - (void)sendErrorString:(NSString*)error {
   DLOG(ERROR) << [error UTF8String];
   [lock_ lock];
   if (frameReceiver_)
     frameReceiver_->ReceiveError([error UTF8String]);
   [lock_ unlock];
 }
 
 @end