Chrome: 64.0.3271.0

Repro steps:
1. Add log print-out in FocusManager::ProcessAccelerator(), including stack-trace.
2. Run Chrome w/ logging enabled.
3. Press the Alt key.

Expectation is that ProcessAccelerator() will be called once per key event, since there is either an accelerator, or there isn't.

In practice there are two calls to ProcessAccelerator():

One when "pre-handling" the event:
        base::debug::StackTrace::StackTrace [0x0000000000921CD8+104] (C:\src\git-chrome\src\base\debug\stack_trace_win.cc:286)
        views::FocusManager::ProcessAccelerator [0x0000000013DF9E0F+639] (C:\src\git-chrome\src\ui\views\focus\focus_manager.cc:486)
        BrowserView::PreHandleKeyboardEvent [0x000000000CD0317B+539] (C:\src\git-chrome\src\chrome\browser\ui\views\frame\browser_view.cc:1362)
        Browser::PreHandleKeyboardEvent [0x000000000C99D862+130] (C:\src\git-chrome\src\chrome\browser\ui\browser.cc:1252)
        content::WebContentsImpl::PreHandleKeyboardEvent [0x0000000017E988FE+78] (C:\src\git-chrome\src\content\browser\web_contents\web_contents_impl.cc:1983)
        content::RenderWidgetHostImpl::ForwardKeyboardEventWithCommands [0x000000001792B955+1141] (C:\src\git-chrome\src\content\browser\renderer_host\render_widget_host_impl.cc:1350)
        content::RenderWidgetHostViewAura::ForwardKeyboardEventWithLatencyInfo [0x000000001798296A+202] (C:\src\git-chrome\src\content\browser\renderer_host\render_widget_host_view_aura.cc:2343)
        content::RenderWidgetHostViewEventHandler::OnKeyEvent [0x00000000181568F8+1256] (C:\src\git-chrome\src\content\browser\renderer_host\render_widget_host_view_event_handler.cc:288)

and another when processing the keyboard-event ACK:

        base::debug::StackTrace::StackTrace [0x0000000000921CD8+104] (C:\src\git-chrome\src\base\debug\stack_trace_win.cc:286)
        views::FocusManager::ProcessAccelerator [0x0000000013DF9E0F+639] (C:\src\git-chrome\src\ui\views\focus\focus_manager.cc:486)
        views::UnhandledKeyboardEventHandler::HandleKeyboardEvent [0x000000002E3CA8E6+294] (C:\src\git-chrome\src\ui\views\controls\webview\unhandled_keyboard_event_handler.cc:48)
        BrowserView::HandleKeyboardEvent [0x000000000CD0389D+125] (C:\src\git-chrome\src\chrome\browser\ui\views\frame\browser_view.cc:1394)
        Browser::HandleKeyboardEvent [0x000000000C99D92C+140] (C:\src\git-chrome\src\chrome\browser\ui\browser.cc:1265)
        content::WebContentsImpl::HandleKeyboardEvent [0x0000000017E989E4+164] (C:\src\git-chrome\src\content\browser\web_contents\web_contents_impl.cc:1994)
        content::RenderWidgetHostImpl::OnKeyboardEventAck [0x0000000017932B41+433] (C:\src\git-chrome\src\content\browser\renderer_host\render_widget_host_impl.cc:2354)
        content::InputRouterImpl::KeyboardEventHandled [0x0000000017632C94+660] (C:\src\git-chrome\src\content\browser\renderer_host\input\input_router_impl.cc:422)