gfx: Use unsigned strides for gpu memory buffers.

gpu/ipc/client/gpu_memory_buffer_impl_surface_texture.h

 // 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.
 
 #ifndef GPU_IPC_CLIENT_GPU_MEMORY_BUFFER_IMPL_SURFACE_TEXTURE_H_
 #define GPU_IPC_CLIENT_GPU_MEMORY_BUFFER_IMPL_SURFACE_TEXTURE_H_
 
 #include <android/native_window.h>
 #include <stddef.h>
 
@@ skipping 23 matching lines @@
 
   static base::Closure AllocateForTesting(const gfx::Size& size,
                                           gfx::BufferFormat format,
                                           gfx::BufferUsage usage,
                                           gfx::GpuMemoryBufferHandle* handle);
 
   // Overridden from gfx::GpuMemoryBuffer:
   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;
 
  private:
   GpuMemoryBufferImplSurfaceTexture(gfx::GpuMemoryBufferId id,
                                     const gfx::Size& size,
                                     gfx::BufferFormat format,
                                     const DestructionCallback& callback,
                                     ANativeWindow* native_window);
 
   ANativeWindow* native_window_;
   ANativeWindow_Buffer buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuMemoryBufferImplSurfaceTexture);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_IPC_CLIENT_GPU_MEMORY_BUFFER_IMPL_SURFACE_TEXTURE_H_