This is the backtrace of the webbrowser-app crash:

#0  content::RenderWidgetHostImpl::WasHidden (this=0x0)
    at ../../../../third_party/chromium/src/content/browser/renderer_host/render_widget_host_impl.cc:506
#1  0xadada442 in oxide::RenderWidgetHostView::WasHidden (this=0xb7d262a8)
    at ../../../../shared/browser/oxide_render_widget_host_view.cc:192
#2  0xadada61e in oxide::RenderWidgetHostView::~RenderWidgetHostView (
    this=0xb7d262a8, __in_chrg=<optimized out>)
    at ../../../../shared/browser/oxide_render_widget_host_view.cc:548
#3  0xadada750 in oxide::RenderWidgetHostView::~RenderWidgetHostView (
    this=0xb7d262a8, __in_chrg=<optimized out>)
    at ../../../../shared/browser/oxide_render_widget_host_view.cc:549
#4  0xaf1bd4d6 in content::RenderWidgetHostImpl::RendererExited (
    this=this@entry=0xb7c7b670, 
    status=base::TERMINATION_STATUS_PROCESS_WAS_KILLED, 
    exit_code=exit_code@entry=15)
    at ../../../../third_party/chromium/src/content/browser/renderer_host/render_widget_host_impl.cc:1210
#5  0xaf1b22a8 in content::RenderViewHostImpl::OnRenderProcessGone (
    this=0xb7c7b668, status=2, exit_code=15)
    at ../../../../third_party/chromium/src/content/browser/renderer_host/render_view_host_impl.cc:1139
#6  0xaf1b8d4e in DispatchToMethod<content::RenderViewHostImpl, void (content::RenderViewHostImpl::*)(int, int), int, int> (arg=..., method=
    (void (content::RenderViewHostImpl::*)(content::RenderViewHostImpl * const, int, int)) 0xaf1b227d <content::RenderViewHostImpl::OnRenderProcessGone(int, int)>, obj=0xb7c7b668) at ../../../../third_party/chromium/src/base/tuple.h:555
#7  Dispatch<content::RenderViewHostImpl, content::RenderViewHostImpl, void, void (content::RenderViewHostImpl::*)(int, int)> (sender=<optimized out>, 
    parameter=0x0, func=
    (void (content::RenderViewHostImpl::*)(content::RenderViewHostImpl * const, int, int)) 0xaf1b227d <content::RenderViewHostImpl::OnRenderProcessGone(int, int)>, obj=0xb7c7b668, msg=0xbeeceef4)
    at ../../../../third_party/chromium/src/content/common/view_messages.h:1075
#8  content::RenderViewHostImpl::OnMessageReceived (this=0xb7c7b668, msg=...)
    at ../../../../third_party/chromium/src/content/browser/renderer_host/render_view_host_impl.cc:977
#9  0xaf1b1036 in content::RenderProcessHostImpl::ProcessDied (
    this=0xb7c4a138, already_dead=<optimized out>)
    at ../../../../third_party/chromium/src/content/browser/renderer_host/render_process_host_impl.cc:1939
#10 0xadb1dab6 in Run (this=0xbeecf060)
    at ../../../../third_party/chromium/src/base/callback.h:401
#11 base::MessageLoop::RunTask (this=this@entry=0xb7a29430, pending_task=...)
    at ../../../../third_party/chromium/src/base/message_loop/message_loop.cc:450
#12 0xadb1e046 in base::MessageLoop::DeferOrRunPendingTask (
    this=this@entry=0xb7a29430, pending_task=...)
    at ../../../../third_party/chromium/src/base/message_loop/message_loop.cc:462
#13 0xadb1fe74 in base::MessageLoop::DoWork (this=0xb7a29430)
    at ../../../../third_party/chromium/src/base/message_loop/message_loop.cc:576
#14 0xadabbc9c in oxide::qt::MessagePump::customEvent (this=0xb7a288a0, 
    event=<optimized out>)
    at ../../../../qt/core/browser/oxide_qt_message_pump.cc:60
#15 0xb6da1064 in QObject::event(QEvent*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5
#16 0xb60829a4 in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Widgets.so.5
#17 0xb608613a in QApplication::notify(QObject*, QEvent*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Widgets.so.5
Backtrace stopped: Cannot access memory at address 0x2d4ff0e0

The real issue is that the renderer process was terminated. However the browser app shouldn’t crash when that happens. The above stacktrace looks very much like bug #1337338, which I’ll re-open.