fix sign-compare warning.

content/common/gpu/media/exynos_v4l2_video_device.cc

 // Copyright 2014 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.
 //
 
 #include <fcntl.h>
 #include <libdrm/drm_fourcc.h>
 #include <linux/videodev2.h>
 #include <poll.h>
 #include <sys/eventfd.h>
@@ skipping 141 matching lines @@
     memset(&expbuf, 0, sizeof(expbuf));
     expbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
     expbuf.index = buffer_index;
     expbuf.plane = i;
     expbuf.flags = O_CLOEXEC;
     if (Ioctl(VIDIOC_EXPBUF, &expbuf) != 0) {
       return EGL_NO_IMAGE_KHR;
     }
     dmabuf_fds[i].reset(expbuf.fd);
   }
-  DCHECK_EQ(planes_count, 2);
+  DCHECK_EQ(planes_count, 2u);
   EGLint attrs[] = {
       EGL_WIDTH,                     0, EGL_HEIGHT,                    0,
       EGL_LINUX_DRM_FOURCC_EXT,      0, EGL_DMA_BUF_PLANE0_FD_EXT,     0,
       EGL_DMA_BUF_PLANE0_OFFSET_EXT, 0, EGL_DMA_BUF_PLANE0_PITCH_EXT,  0,
       EGL_DMA_BUF_PLANE1_FD_EXT,     0, EGL_DMA_BUF_PLANE1_OFFSET_EXT, 0,
       EGL_DMA_BUF_PLANE1_PITCH_EXT,  0, EGL_NONE, };
   attrs[1] = frame_buffer_size.width();
   attrs[3] = frame_buffer_size.height();
   attrs[5] = DRM_FORMAT_NV12;
   attrs[7] = dmabuf_fds[0].get();
@@ skipping 29 matching lines @@
 }
 
 uint32 ExynosV4L2Device::PreferredOutputFormat() {
   // TODO(posciak): We should support "dontcare" returns here once we
   // implement proper handling (fallback, negotiation) for this in users.
   CHECK_EQ(type_, kDecoder);
   return V4L2_PIX_FMT_NV12M;
 }
 
 }  //  namespace content