Add ExtensionsApiClient interface, use it in the storage API SettingsFrontend

chrome/browser/extensions/chrome_extensions_browser_client.cc

Index: chrome/browser/extensions/chrome_extensions_browser_client.cc
diff --git a/chrome/browser/extensions/chrome_extensions_browser_client.cc b/chrome/browser/extensions/chrome_extensions_browser_client.cc
index b63298af0f08b2ad5c7d2da422da72e03e5c66bd..0ebf3a347019b297400d3e9c0de2b55f5a8f990f 100644
--- a/chrome/browser/extensions/chrome_extensions_browser_client.cc
+++ b/chrome/browser/extensions/chrome_extensions_browser_client.cc
@@ -9,6 +9,7 @@
 #include "chrome/browser/app_mode/app_mode_utils.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/activity_log/activity_log.h"
+#include "chrome/browser/extensions/api/chrome_extensions_api_client.h"
 #include "chrome/browser/extensions/chrome_app_sorting.h"
 #include "chrome/browser/extensions/extension_host.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ -33,13 +34,18 @@
 
 namespace extensions {
 
-ChromeExtensionsBrowserClient::ChromeExtensionsBrowserClient() {
+ChromeExtensionsBrowserClient::ChromeExtensionsBrowserClient()
+    : api_client_(new ChromeExtensionsApiClient) {
+  ExtensionsApiClient::Set(api_client_.get());

[Devlin, 2014/03/03 17:07:59]

I'm quite certain I'm paranoid here, but I might prefer this to go into
ExtensionsApiClient's constructor/destructor, so that we are sure to set
appropriately (pending any option to deliberately reset a client).

[James Cook, 2014/03/03 19:53:09]

SGTM. Done.

+
   // Only set if it hasn't already been set (e.g. by a test).
   if (GetCurrentChannel() == GetDefaultChannel())
     SetCurrentChannel(chrome::VersionInfo::GetChannel());
 }
 
-ChromeExtensionsBrowserClient::~ChromeExtensionsBrowserClient() {}
+ChromeExtensionsBrowserClient::~ChromeExtensionsBrowserClient() {
+  ExtensionsApiClient::Set(NULL);
+}
 
 bool ChromeExtensionsBrowserClient::IsShuttingDown() {
   return g_browser_process->IsShuttingDown();