Android: Remove more unneeded bits.

chrome/browser/extensions/chrome_extension_host_delegate.cc

Index: chrome/browser/extensions/chrome_extension_host_delegate.cc
diff --git a/chrome/browser/extensions/chrome_extension_host_delegate.cc b/chrome/browser/extensions/chrome_extension_host_delegate.cc
index 2b23d82390c2acaa333f8b138c801a257ccb14ba..57de1403ec847ae0e9cffd59d89f974b04b10c2d 100644
--- a/chrome/browser/extensions/chrome_extension_host_delegate.cc
+++ b/chrome/browser/extensions/chrome_extension_host_delegate.cc
@@ -4,7 +4,6 @@
 
 #include "chrome/browser/extensions/chrome_extension_host_delegate.h"
 
-#include "chrome/browser/extensions/chrome_extension_web_contents_observer.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/media/media_capture_devices_dispatcher.h"
@@ -13,6 +12,11 @@
 #include "extensions/browser/extension_host.h"
 #include "extensions/browser/extension_system.h"
 
+// TODO(thestig): Remove #ifdefs when extensions is disabled on mobile.
+#if defined(ENABLE_EXTENSIONS)
+#include "chrome/browser/extensions/chrome_extension_web_contents_observer.h"
+#endif
+
 namespace extensions {
 
 ChromeExtensionHostDelegate::ChromeExtensionHostDelegate() {}
@@ -21,7 +25,9 @@ ChromeExtensionHostDelegate::~ChromeExtensionHostDelegate() {}
 
 void ChromeExtensionHostDelegate::OnExtensionHostCreated(
     content::WebContents* web_contents) {
+#if defined(ENABLE_EXTENSIONS)
   ChromeExtensionWebContentsObserver::CreateForWebContents(web_contents);

[not at google - send to devlin, 2014/07/08 15:18:14]

there is going to be a lot of this. would it make sense to have some utility
like "CreateForWebContentsIfSupported" which does nothing on Android (and use
that basically everywhere).

[Lei Zhang, 2014/07/08 20:41:13]

There are many, but a good percentage of them are in code that's not being
built, and most of the rest have been ifdefed already. This is in fact the last
one that I need to ifdef out.

+#endif
   PrefsTabHelper::CreateForWebContents(web_contents);
 }