[Dashboard] Remove Legacy Dashboard Only Mode

.github/CODEOWNERS

@@ -144,7 +144,6 @@
 /x-pack/plugins/dashboard_enhanced/ @elastic/kibana-presentation
 /x-pack/test/functional/apps/canvas/  @elastic/kibana-presentation
 #CC# /src/plugins/kibana_react/public/code_editor/ @elastic/kibana-presentation
-#CC# /x-pack/plugins/dashboard_mode @elastic/kibana-presentation
 
 # Machine Learning
 /x-pack/plugins/ml/  @elastic/ml-ui

docs/developer/plugin-list.asciidoc

@@ -378,10 +378,6 @@ The client-side plugin configures following values:
 |Adds drilldown capabilities to dashboard.  Owned by the Kibana App team.
 
 
-|{kib-repo}blob/{branch}/x-pack/plugins/dashboard_mode/README.md[dashboardMode]
-|The deprecated dashboard only mode.
-
-
 |{kib-repo}blob/{branch}/x-pack/plugins/data_enhanced/README.md[dataEnhanced]
 |The data_enhanced plugin is the x-pack counterpart to the src/plguins/data plugin.
 

docs/development/core/public/kibana-plugin-core-public.chromenavlinks.md

@@ -22,5 +22,4 @@ export interface ChromeNavLinks
 |  [getForceAppSwitcherNavigation$()](./kibana-plugin-core-public.chromenavlinks.getforceappswitchernavigation_.md) | An observable of the forced app switcher state. |
 |  [getNavLinks$()](./kibana-plugin-core-public.chromenavlinks.getnavlinks_.md) | Get an observable for a sorted list of navlinks. |
 |  [has(id)](./kibana-plugin-core-public.chromenavlinks.has.md) | Check whether or not a navlink exists. |
-|  [showOnly(id)](./kibana-plugin-core-public.chromenavlinks.showonly.md) | Remove all navlinks except the one matching the given id. |
 

packages/kbn-optimizer/limits.yml

@@ -12,7 +12,6 @@ pageLoadAssetSize:
   crossClusterReplication: 65408
   dashboard: 374194
   dashboardEnhanced: 65646
-  dashboardMode: 22716
   data: 824229
   dataEnhanced: 50420
   devTools: 38637

src/core/public/chrome/chrome_service.mock.ts

@@ -19,7 +19,6 @@ const createStartContractMock = () => {
       has: jest.fn(),
       get: jest.fn(),
       getAll: jest.fn(),
-      showOnly: jest.fn(),
       enableForcedAppSwitcherNavigation: jest.fn(),
       getForceAppSwitcherNavigation$: jest.fn(),
     },