Support Using ScopedFeatureList in BrowserTest

base/command_line.cc

Index: base/command_line.cc
diff --git a/base/command_line.cc b/base/command_line.cc
index 873da813483651bc9e74b0510e17fa925225b5bd..1b319ec814f3782c28d45936265cb2b8818b7f57 100644
--- a/base/command_line.cc
+++ b/base/command_line.cc
@@ -365,6 +365,20 @@ void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 #endif
 }
 
+void CommandLine::RemoveSwitchASCIIForTesting(
+    const std::string& switch_string) {
+#if defined(OS_WIN)
+  const std::string switch_key = ToLowerASCII(switch_string);
+  StringType combined_switch_string(ASCIIToUTF16(switch_key));
+#elif defined(OS_POSIX)
+  const std::string& switch_key = switch_string;
+  StringType combined_switch_string(switch_key);
+#endif

[Ilya Sherman, 2017/06/07 21:32:36]

These few lines are duplicated from above.  Please factor out a small helper
function for this rather than copy/pasting them.

+  size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
+  switches_by_stringpiece_.erase(switch_key.substr(prefix_length));
+  switches_.erase(switch_string.substr(prefix_length));

[Ilya Sherman, 2017/06/07 21:32:36]

Does argv_ need to be updated as well?  (I am not familiar with the details of
the CommandLine implementation, so I'm just judging by the fact that it's set in
AppendSwitchNative().)

+}
+
 void CommandLine::CopySwitchesFrom(const CommandLine& source,
                                    const char* const switches[],
                                    size_t count) {