Add DevTools check to CrashKeys for crbug.com/824774.

Record whether DevTools is currently active in CrashKeys.

Bug: 824774
Change-Id: I697bf892037c63216890d9d5f7ccc67e037f3b19
Reviewed-on: https://chromium-review.googlesource.com/986453
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546929}

content/browser/renderer_host/render_widget_host_input_event_router.cc

@@ -1192,11 +1192,22 @@ void RenderWidgetHostInputEventRouter::DispatchTouchscreenGestureEvent(
   event.SetPositionInWidget(event.PositionInWidget() +
                             touchscreen_gesture_target_.delta);
   // Temporary logging for https://crbug.com/824774.
+  // TODO(wjmaclean): Remove all this logging code once the issue is resolved.
   static auto* target_ptr_key = base::debug::AllocateCrashKeyString(
       "touchscreen-gesture-target-ptr", base::debug::CrashKeySize::Size64);
   base::debug::SetCrashKeyString(
       target_ptr_key,
       base::StringPrintf("%p", touchscreen_gesture_target_.target));
+  // Issue 824772 is a potential cause for issue 824774. Report whether
+  // devtools is in use to investigate this possibility.
+  auto* contents = root_view->host()->delegate()->GetAsWebContents();
+  const bool have_devtools =
+      contents && DevToolsAgentHost::IsDebuggerAttached(contents);
+  static auto* devtools_key = base::debug::AllocateCrashKeyString(
+      "touchscreen-gesture-target-have-devtools",
+      base::debug::CrashKeySize::Size32);
+  base::debug::SetCrashKeyString(devtools_key, std::to_string(have_devtools));
+  // Crash in 824774 appears to happen on next line.
   touchscreen_gesture_target_.target->ProcessGestureEvent(event, latency);
 }