gfx: Use unsigned strides for gpu memory buffers.

components/display_compositor/buffer_queue_unittest.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 "components/display_compositor/buffer_queue.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <set>
@@ skipping 23 matching lines @@
       : set_color_space_count_(set_color_space_count) {}
 
   // Overridden from gfx::GpuMemoryBuffer:
   bool Map() override { return false; }
   void* memory(size_t plane) override { return nullptr; }
   void Unmap() override {}
   gfx::Size GetSize() const override { return gfx::Size(); }
   gfx::BufferFormat GetFormat() const override {
     return gfx::BufferFormat::BGRX_8888;
   }
-  int stride(size_t plane) const override { return 0; }
+  uint32_t stride(size_t plane) const override { return 0u; }
   gfx::GpuMemoryBufferId GetId() const override {
     return gfx::GpuMemoryBufferId(0);
   }
   void SetColorSpaceForScanout(const gfx::ColorSpace& color_space) override {
     *set_color_space_count_ += 1;
   }
   gfx::GpuMemoryBufferHandle GetHandle() const override {
     return gfx::GpuMemoryBufferHandle();
   }
   ClientBuffer AsClientBuffer() override {
@@ skipping 616 matching lines @@
   testing::Mock::VerifyAndClearExpectations(mock_output_surface_);
   EXPECT_CALL(*mock_output_surface_,
               CopyBufferDamage(target_texture, source_texture, small_damage, _))
       .Times(1);
   output_surface_->SwapBuffers(small_damage);
   testing::Mock::VerifyAndClearExpectations(mock_output_surface_);
 }
 
 }  // namespace
 }  // namespace display_compositor