gfx: Use unsigned strides for gpu memory buffers.

services/ui/public/cpp/mojo_gpu_memory_buffer.cc

Index: services/ui/public/cpp/mojo_gpu_memory_buffer.cc
diff --git a/services/ui/public/cpp/mojo_gpu_memory_buffer.cc b/services/ui/public/cpp/mojo_gpu_memory_buffer.cc
index c0d776b567487378ccd1469d8b4cb33a800c2359..88ed1f6165dea6f9b42a8ce34a28ab3140173f08 100644
--- a/services/ui/public/cpp/mojo_gpu_memory_buffer.cc
+++ b/services/ui/public/cpp/mojo_gpu_memory_buffer.cc
@@ -43,7 +43,7 @@ std::unique_ptr<gfx::GpuMemoryBuffer> MojoGpuMemoryBufferImpl::Create(
 
   auto shared_memory =
       base::MakeUnique<base::SharedMemory>(platform_handle, readonly);
-  const int stride = base::checked_cast<int>(
+  const uint32_t stride = base::checked_cast<uint32_t>(
       gfx::RowSizeForBufferFormat(size.width(), format, 0));
   return base::WrapUnique(new MojoGpuMemoryBufferImpl(
       size, format, std::move(shared_memory), 0, stride));
@@ -98,9 +98,9 @@ void MojoGpuMemoryBufferImpl::Unmap() {
   mapped_ = false;
 }
 
-int MojoGpuMemoryBufferImpl::stride(size_t plane) const {
+uint32_t MojoGpuMemoryBufferImpl::stride(size_t plane) const {
   DCHECK_LT(plane, gfx::NumberOfPlanesForBufferFormat(format_));
-  return base::checked_cast<int>(gfx::RowSizeForBufferFormat(
+  return base::checked_cast<uint32_t>(gfx::RowSizeForBufferFormat(
       size_.width(), format_, static_cast<int>(plane)));
 }
 
@@ -123,7 +123,7 @@ MojoGpuMemoryBufferImpl::MojoGpuMemoryBufferImpl(
     gfx::BufferFormat format,
     std::unique_ptr<base::SharedMemory> shared_memory,
     uint32_t offset,
-    int32_t stride)
+    uint32_t stride)
     : GpuMemoryBufferImpl(gfx::GenericSharedMemoryId(0), size, format),
       shared_memory_(std::move(shared_memory)),
       offset_(offset),