[ios] Move ChromeBrowserState to global namespace

Move ChromeBrowserState to the global namespace and add "using"
to also make it accessible through the "ios" namespace. Change
the forward declaration in chrome_browser_state_forward.h to
also use the same pattern.

Bug: 1042208
Change-Id: I721e2e6976bce5110724f66b0dfa3edd8acdfd37
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2014913
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734497}

ios/chrome/browser/browser_state/chrome_browser_state.h

@@ -35,8 +35,6 @@ namespace web {
 class WebUIIOS;
 }
 
-namespace ios {
-
 enum class ChromeBrowserStateType {
   REGULAR_BROWSER_STATE,
   INCOGNITO_BROWSER_STATE,
@@ -133,6 +131,9 @@ class ChromeBrowserState : public web::BrowserState {
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserState);
 };
 
+namespace ios {
+using ::ChromeBrowserState;
+using ::ChromeBrowserStateType;
 }  // namespace ios
 
 #endif  // IOS_CHROME_BROWSER_BROWSER_STATE_CHROME_BROWSER_STATE_H_

ios/chrome/browser/browser_state/chrome_browser_state.mm

@@ -24,7 +24,6 @@
 #error "This file requires ARC support."
 #endif
 
-namespace ios {
 namespace {
 // All ChromeBrowserState will store a dummy base::SupportsUserData::Data
 // object with this key. It can be used to check that a web::BrowserState
@@ -95,5 +94,3 @@ void ChromeBrowserState::UpdateCorsExemptHeader(
     network::mojom::NetworkContextParams* params) {
   variations::UpdateCorsExemptHeaderForVariations(params);
 }
-
-}  // namespace ios

ios/chrome/browser/browser_state/chrome_browser_state_forward.h

@@ -8,9 +8,12 @@
 // This file is there to help move ios::ChromeBrowserState to the global
 // namespace (i.e. rename it to ChromeBrowserState).
 
-namespace ios {
 class ChromeBrowserState;
 enum class ChromeBrowserStateType;
+
+namespace ios {
+using ::ChromeBrowserState;
+using ::ChromeBrowserStateType;
 }  // namespace ios
 
 #endif  // IOS_CHROME_BROWSER_BROWSER_STATE_CHROME_BROWSER_STATE_FORWARD_H_