Fixes for re-enabling more MSVC level 4 warnings: gpu/ edition

gpu/command_buffer/client/transfer_buffer_unittest.cc

Index: gpu/command_buffer/client/transfer_buffer_unittest.cc
diff --git a/gpu/command_buffer/client/transfer_buffer_unittest.cc b/gpu/command_buffer/client/transfer_buffer_unittest.cc
index 9f3b51e47503d1d3744179cc1c98cbd2aaf62d8c..cb8558fe4f34f00d9a75627b7914517ae3143584 100644
--- a/gpu/command_buffer/client/transfer_buffer_unittest.cc
+++ b/gpu/command_buffer/client/transfer_buffer_unittest.cc
@@ -185,7 +185,7 @@ TEST_F(TransferBufferTest, MemoryAlignmentAfterZeroAllocation) {
   Initialize(32u);
   void* ptr = transfer_buffer_->Alloc(0);
   EXPECT_EQ((reinterpret_cast<uintptr_t>(ptr) & (kAlignment - 1)), 0u);
-  transfer_buffer_->FreePendingToken(ptr, -1);
+  transfer_buffer_->FreePendingToken(ptr, static_cast<unsigned int>(-1));
   // Check that the pointer is aligned on the following allocation.
   ptr = transfer_buffer_->Alloc(4);
   EXPECT_EQ((reinterpret_cast<uintptr_t>(ptr) & (kAlignment - 1)), 0u);