gfx: Use unsigned strides for gpu memory buffers.

services/ui/public/cpp/mojo_gpu_memory_buffer.h

Index: services/ui/public/cpp/mojo_gpu_memory_buffer.h
diff --git a/services/ui/public/cpp/mojo_gpu_memory_buffer.h b/services/ui/public/cpp/mojo_gpu_memory_buffer.h
index fe9bc6030eee06ae23ebccc359b4c307834330cd..9eae46f99afcf5c159c349af94a94829c17d3401 100644
--- a/services/ui/public/cpp/mojo_gpu_memory_buffer.h
+++ b/services/ui/public/cpp/mojo_gpu_memory_buffer.h
@@ -36,7 +36,7 @@ class MojoGpuMemoryBufferImpl : public ui::GpuMemoryBufferImpl {
   bool Map() override;
   void* memory(size_t plane) override;
   void Unmap() override;
-  int stride(size_t plane) const override;
+  uint32_t stride(size_t plane) const override;
   gfx::GpuMemoryBufferHandle GetHandle() const override;
 
   // Overridden from gfx::GpuMemoryBufferImpl
@@ -47,11 +47,11 @@ class MojoGpuMemoryBufferImpl : public ui::GpuMemoryBufferImpl {
                           gfx::BufferFormat format,
                           std::unique_ptr<base::SharedMemory> shared_memory,
                           uint32_t offset,
-                          int32_t stride);
+                          uint32_t stride);
 
   std::unique_ptr<base::SharedMemory> shared_memory_;
   const uint32_t offset_;
-  const int32_t stride_;
+  const uint32_t stride_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoGpuMemoryBufferImpl);
 };