gfx: Use unsigned strides for gpu memory buffers.

gpu/command_buffer/tests/gl_manager.cc

Index: gpu/command_buffer/tests/gl_manager.cc
diff --git a/gpu/command_buffer/tests/gl_manager.cc b/gpu/command_buffer/tests/gl_manager.cc
index 6d6658cb73d90e44790fcb8e779b88beb5f161d2..3be8aa911276bb7835a35ede03e2eb1c4ac96583 100644
--- a/gpu/command_buffer/tests/gl_manager.cc
+++ b/gpu/command_buffer/tests/gl_manager.cc
@@ -84,7 +84,7 @@ class GpuMemoryBufferImpl : public gfx::GpuMemoryBuffer {
   }
   gfx::Size GetSize() const override { return size_; }
   gfx::BufferFormat GetFormat() const override { return format_; }
-  int stride(size_t plane) const override {
+  uint32_t stride(size_t plane) const override {
     DCHECK_LT(plane, gfx::NumberOfPlanesForBufferFormat(format_));
     return gfx::RowSizeForBufferFormat(size_.width(), format_, plane);
   }
@@ -142,7 +142,7 @@ class IOSurfaceGpuMemoryBuffer : public gfx::GpuMemoryBuffer {
   }
   gfx::Size GetSize() const override { return size_; }
   gfx::BufferFormat GetFormat() const override { return format_; }
-  int stride(size_t plane) const override {
+  uint32_t stride(size_t plane) const override {
     DCHECK_LT(plane, gfx::NumberOfPlanesForBufferFormat(format_));
     return IOSurfaceGetWidthOfPlane(iosurface_, plane);
   }