Remove ChromeBrowserProvider::GetLiveTabContextProvider() method.

ios/chrome/browser/downstream_chromium_browser_provider.h

Index: ios/chrome/browser/downstream_chromium_browser_provider.h
diff --git a/ios/chrome/browser/downstream_chromium_browser_provider.h b/ios/chrome/browser/downstream_chromium_browser_provider.h
index 32ec14fac6256374c909cf09ee0c86226dccf41c..5ec2f17cac825027494a600f75cf9b736f010130 100644
--- a/ios/chrome/browser/downstream_chromium_browser_provider.h
+++ b/ios/chrome/browser/downstream_chromium_browser_provider.h
@@ -19,7 +19,6 @@ class DownstreamChromiumBrowserProvider : public ChromiumBrowserProvider {
   // ChromeBrowserProvider implementations.  All of these will move upstream
   // into ChromiumBrowserProvider eventually, and from there callers will be
   // converted to not go through the provider API at all.
-  ios::LiveTabContextProvider* GetLiveTabContextProvider() override;
   void SetUIViewAlphaWithAnimation(UIView* view, float alpha) override;
   autofill::CardUnmaskPromptView* CreateCardUnmaskPromptView(
       autofill::CardUnmaskPromptController* controller) override;
@@ -33,9 +32,6 @@ class DownstreamChromiumBrowserProvider : public ChromiumBrowserProvider {
   CreateSyncedWindowDelegatesGetter(
       ios::ChromeBrowserState* browser_state) override;
 
-  std::unique_ptr<ios::LiveTabContextProvider>
-      tab_restore_service_delegate_provider_;
-
   DISALLOW_COPY_AND_ASSIGN(DownstreamChromiumBrowserProvider);
 };