Reland: Add ExtensionsApiClient interface, use it in the storage API SettingsFrontend

app_shell needs the chrome.storage.local extension API so the core storage implementation is moving to //extensions/browser/api. However, the "managed storage" API implementation needs to remain in Chrome.

* Introduce ExtensionsApiClient in extensions/browser/api
* Introduce ChromeExtensionsApiClient in chrome/browser/extensions/api
* Delegate out the storage ManagedValueStoreCache creation to Chrome
* Move settings_namespace.h/cc to e/b/api/storage so we can use an enum in the client interface definition

Most APIs will probably need to make only one or two client interface calls, so we're starting with a single ExtensionsApiClient interface. It we find individual APIs tend to need a lot of methods we can split it into one client interface per API, but that seems like overkill right now.

Reland of https://codereview.chromium.org/180213008/ with fixes for Android GCMProfileServiceSingleProfileTest.Unregister

BUG=348058
TEST=unit_tests *Settings* and browser_tests ExtensionSettings*
TBR=rdevlin.cronin@chromium.org, rockot@chromium.org, yoz@chromium.org

Review URL: https://codereview.chromium.org/184853012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255384 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 7 insertions, 2 deletions

diff --git a/apps/shell/browser/shell_extensions_browser_client.cc b/apps/shell/browser/shell_extensions_browser_client.cc
index 8089b5e..7245960 100644
--- a/apps/shell/browser/shell_extensions_browser_client.cc
+++ b/apps/shell/browser/shell_extensions_browser_client.cc
@@ -12,6 +12,7 @@
 #include "chrome/common/extensions/api/generated_api.h"
 #include "components/user_prefs/pref_registry_syncable.h"
 #include "components/user_prefs/user_prefs.h"
+#include "extensions/browser/api/extensions_api_client.h"
 #include "extensions/browser/app_sorting.h"
 #include "extensions/browser/extension_prefs.h"
 
@@ -27,10 +28,9 @@ void RegisterPrefs(user_prefs::PrefRegistrySyncable* registry) {
 
 }  // namespace
 
-
 ShellExtensionsBrowserClient::ShellExtensionsBrowserClient(
     BrowserContext* context)
-    : browser_context_(context) {
+    : browser_context_(context), api_client_(new ExtensionsAPIClient) {
   // Set up the preferences service.
   base::PrefServiceFactory factory;
   factory.set_user_prefs(new TestingPrefStore);
diff --git a/apps/shell/browser/shell_extensions_browser_client.h b/apps/shell/browser/shell_extensions_browser_client.h
index 529f37b..55b7f49 100644
--- a/apps/shell/browser/shell_extensions_browser_client.h
+++ b/apps/shell/browser/shell_extensions_browser_client.h
@@ -12,6 +12,8 @@ class PrefService;
 
 namespace extensions {
 
+class ExtensionsAPIClient;
+
 // An ExtensionsBrowserClient that supports a single content::BrowserContent
 // with no related incognito context.
 class ShellExtensionsBrowserClient : public ExtensionsBrowserClient {
@@ -65,6 +67,9 @@ class ShellExtensionsBrowserClient : public ExtensionsBrowserClient {
   // The single BrowserContext for app_shell. Not owned.
   content::BrowserContext* browser_context_;
 
+  // Support for extension APIs.
+  scoped_ptr<ExtensionsAPIClient> api_client_;
+
   // The PrefService for |browser_context_|.
   scoped_ptr<PrefService> prefs_;