Create --disable-extensions-except switch

chrome/browser/extensions/extension_startup_browsertest.cc

Index: chrome/browser/extensions/extension_startup_browsertest.cc
diff --git a/chrome/browser/extensions/extension_startup_browsertest.cc b/chrome/browser/extensions/extension_startup_browsertest.cc
index 462f2ba9d06049f078fcec1192e2ce90b9632be5..a05123f46e2d6e7ae2c58bebc477cf5d79793425 100644
--- a/chrome/browser/extensions/extension_startup_browsertest.cc
+++ b/chrome/browser/extensions/extension_startup_browsertest.cc
@@ -16,6 +16,7 @@
 #include "base/strings/stringprintf.h"
 #include "build/build_config.h"
 #include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/extensions/extension_browsertest.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/extensions/shared_user_script_master.h"
@@ -42,6 +43,7 @@
 #include "net/base/filename_util.h"
 
 using extensions::FeatureSwitch;
+using extensions::ExtensionRegistry;
 
 // This file contains high-level startup tests for the extensions system. We've
 // had many silly bugs where command line flags did not get propagated correctly
@@ -311,3 +313,50 @@ IN_PROC_BROWSER_TEST_F(ExtensionsLoadMultipleTest, Test) {
   WaitForServicesToStart(4, true);
   TestInjection(true, true);
 }
+
+// DisableExtensionsExceptBrowserTest

[Devlin, 2016/07/25 19:10:29]

This line probably isn't necessary.

[catmullings, 2016/07/27 01:29:45]

Done.

+// Ensures that the --disable-extesions-except command line flag disables

[Devlin, 2016/07/25 19:10:30]

This sounds like a test description, rather than a class description.

[catmullings, 2016/07/27 01:29:45]

Done.

[catmullings, 2016/07/27 01:29:46]

I will just remove it. 

+// all extensions except those listed.
+class DisableExtensionsExceptBrowserTest : public ExtensionBrowserTest {
+ public:
+  DisableExtensionsExceptBrowserTest() {}
+
+  void SetUpCommandLine(base::CommandLine* command_line) override;
+
+  ExtensionRegistry* GetExtensionRegistry() {
+    return ExtensionRegistry::Get(browser()->profile());
+  }
+};
+
+// Adds --disable-extesions-except command line flag.

[Devlin, 2016/07/25 19:10:29]

Since this is pretty obvious from the code, I'd omit it.

[catmullings, 2016/07/27 01:29:45]

Done.

+void DisableExtensionsExceptBrowserTest::SetUpCommandLine(
+    base::CommandLine* command_line) {
+  ExtensionBrowserTest::SetUpCommandLine(command_line);
+
+  command_line->AppendSwitchASCII(
+      switches::kDisableExtensionsExcept,
+      "chrome/test/data/extensions/app_dot_com_app/");

[Devlin, 2016/07/25 19:10:30]

Can we test with multiple extensions, too?

Also, are we sure this path specification works on all platforms?  I could see
this having problems on windows where paths use \ instead of /.

[catmullings, 2016/07/27 01:29:46]

Done.

+}
+
+// Tests disabling all extensions except those listed
+// (--disable-extensions-except).
+IN_PROC_BROWSER_TEST_F(DisableExtensionsExceptBrowserTest,
+                       DisableExtensionsExceptFlag) {
+  EXPECT_FALSE(extension_service()->extensions_enabled());
+
+  // Count the number of component extensions.
+  int component_extensions = 0;
+  for (const scoped_refptr<const extensions::Extension>& extension :
+       GetExtensionRegistry()->enabled_extensions()) {
+    if (extension->location() == extensions::Manifest::COMPONENT)

[Devlin, 2016/07/25 19:10:29]

prefer Manifest::IsComponentLocation() over comparing directly to
Manifest::Component

[Devlin, 2016/07/25 19:10:30]

optional fanciness:
component_extensions += Manifest::IsComponentLocation(extension->location()) ? 1
: 0;

[catmullings, 2016/07/27 01:29:46]

Done.

[catmullings, 2016/07/27 01:29:46]

Done.

+      component_extensions++;
+  }
+
+  // Number of enabled extensions should be the sum of the number of component
+  // extensions and the of number extensions installed with
+  // --disable-extensions-except.
+  int num_expected_extensions = component_extensions + 1;
+
+  EXPECT_EQ(static_cast<uint32_t>(num_expected_extensions),

[Devlin, 2016/07/25 19:10:29]

Why not instantiate num_expected_extensions as size_t?

[catmullings, 2016/07/27 01:29:46]

Done.

+            GetExtensionRegistry()->enabled_extensions().size());

[Devlin, 2016/07/25 19:10:30]

Can we also check that the other extension is the expected extension?

[catmullings, 2016/07/27 01:29:46]

Done.

+}