gfx: Use unsigned strides for gpu memory buffers.

gpu/ipc/client/gpu_memory_buffer_impl_io_surface.cc

 // 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.
 
 #include "gpu/ipc/client/gpu_memory_buffer_impl_io_surface.h"
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "gpu/ipc/common/gpu_memory_buffer_support.h"
 #include "ui/gfx/buffer_format_util.h"
@@ skipping 87 matching lines @@
   DCHECK_LT(plane, gfx::NumberOfPlanesForBufferFormat(format_));
   return IOSurfaceGetBaseAddressOfPlane(io_surface_, plane);
 }
 
 void GpuMemoryBufferImplIOSurface::Unmap() {
   DCHECK(mapped_);
   IOSurfaceUnlock(io_surface_, lock_flags_, NULL);
   mapped_ = false;
 }
 
-int GpuMemoryBufferImplIOSurface::stride(size_t plane) const {
+uint32_t GpuMemoryBufferImplIOSurface::stride(size_t plane) const {
   DCHECK_LT(plane, gfx::NumberOfPlanesForBufferFormat(format_));
   return IOSurfaceGetBytesPerRowOfPlane(io_surface_, plane);
 }
 
 void GpuMemoryBufferImplIOSurface::SetColorSpaceForScanout(
     const gfx::ColorSpace& color_space) {
   if (color_space == color_space_)
     return;
   color_space_ = color_space;
   std::vector<char> icc_profile =
       gfx::ICCProfile::FromColorSpace(color_space).GetData();
   if (icc_profile.size()) {
     base::ScopedCFTypeRef<CFDataRef> cf_data_icc_profile(CFDataCreate(
         nullptr, reinterpret_cast<const UInt8*>(icc_profile.data()),
         icc_profile.size()));
     IOSurfaceSetValue(io_surface_, CFSTR("IOSurfaceColorSpace"),
                       cf_data_icc_profile);
   }
 }
 
 gfx::GpuMemoryBufferHandle GpuMemoryBufferImplIOSurface::GetHandle() const {
   gfx::GpuMemoryBufferHandle handle;
   handle.type = gfx::IO_SURFACE_BUFFER;
   handle.id = id_;
   return handle;
 }
 
 }  // namespace gpu