Migrate emulation agent to InspectorSessionState fields...

... except for the virtual time properties. I'll do these
separately so it's possible to review them.

Bug:851762

Change-Id: I49333c7e0265cfc855cdb550e6f3338f74d1ebb1
Reviewed-on: https://chromium-review.googlesource.com/1157696
Commit-Queue: Johannes Henkel <johannes@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580335}

third_party/blink/renderer/core/inspector/inspector_emulation_agent.h

@@ -123,6 +123,15 @@ class CORE_EXPORT InspectorEmulationAgent final
   bool enabled_ = false;
 
   InspectorAgentState::String default_background_color_override_rgba_;
+  InspectorAgentState::Boolean script_execution_disabled_;
+  InspectorAgentState::Boolean scrollbars_hidden_;
+  InspectorAgentState::Boolean document_cookie_disabled_;
+  InspectorAgentState::Boolean touch_event_emulation_enabled_;
+  InspectorAgentState::Integer max_touch_points_;
+  InspectorAgentState::String emulated_media_;
+  InspectorAgentState::String navigator_platform_override_;
+  InspectorAgentState::String user_agent_override_;
+  InspectorAgentState::String accept_language_override_;
   DISALLOW_COPY_AND_ASSIGN(InspectorEmulationAgent);
 };