[iOS] Upstream switch and command for reader mode

BUG=429756

Review URL: https://codereview.chromium.org/1141263006

Cr-Commit-Position: refs/heads/master@{#330610}

ios/chrome/browser/chrome_switches.cc

@@ -21,6 +21,9 @@ const char kEnableIOSOpenFromClipboard[] = "enable-ios-open-from-clipboard";
 // Enables the use of WKWebView instead of UIWebView.
 const char kEnableIOSWKWebView[] = "enable-wkwebview";
 
+// Enables context-sensitive reader mode button in the toolbar.
+const char kEnableReaderModeToolbarIcon[] = "enable-reader-mode-toolbar-icon";
+
 // Defines the value in MB of the memory wedge to insert at cold launch.
 const char kIOSMemoryWedgeSize[] = "ios-memory-wedge-size-mb";
 

ios/chrome/browser/chrome_switches.h

@@ -12,6 +12,7 @@ namespace switches {
 extern const char kDisableIOSWKWebView[];
 extern const char kEnableIOSOpenFromClipboard[];
 extern const char kEnableIOSWKWebView[];
+extern const char kEnableReaderModeToolbarIcon[];
 extern const char kIOSMemoryWedgeSize[];
 
 }  // namespace switches

ios/chrome/browser/ui/commands/ios_command_ids.h

@@ -55,6 +55,7 @@
 #define IDC_SHOW_ACCOUNTS_SETTINGS                     40943
 #define IDC_CLOSE_SETTINGS                             40944
 #define IDC_SHOW_SAVE_PASSWORDS_SETTINGS               40945
+#define IDC_READER_MODE                                40947
 // Do not use IDs above 40999 while the iOS build still depends on //chrome, to
 // avoid conflicts.
 // TODO(droger): Remove this comment once iOS no longer depends on //chrome.