Suppression for crbug.com/489779.

BUG=489779
TBR=jam@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1142093003

Cr-Commit-Position: refs/heads/master@{#330567}

tools/valgrind/drmemory/suppressions_full.txt

@@ -1980,3 +1980,14 @@ base.dll!base::SharedMemory::CreateAnonymous
 content.dll!content::ChildThreadImpl::AllocateSharedMemory
 ...
 content.dll!content::PepperPluginInstanceImpl::PrepareTextureMailbox
+
+HANDLE LEAK
+name=https://crbug.com/489779
+system call NtUserCreateWindowEx
+USER32.dll!UnregisterClassW
+USER32.dll!UnregisterClassW
+USER32.dll!CreateWindowExW
+gfx.dll!gfx::WindowImpl::Init
+win_window.dll!ui::WinWindow::WinWindow
+aura.dll!aura::WindowTreeHostWin::WindowTreeHostWin
+aura.dll!aura::WindowTreeHost::Create