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..56a7aa863455ea5abf14044ee5a310e15f6df849 100644
--- a/base/command_line.cc
+++ b/base/command_line.cc
@@ -10,6 +10,7 @@
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/stl_util.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_tokenizer.h"
 #include "base/strings/string_util.h"
@@ -148,6 +149,22 @@ string16 QuoteForCommandLineToArgvW(const string16& arg,
 }
 #endif
 
+std::string GetSwitchKey(const std::string& switch_string) {
+#if defined(OS_WIN)
+  return ToLowerASCII(switch_string);
+#elif defined(OS_POSIX)
+  return switch_string;
+#endif
+}
+
+CommandLine::StringType GetCombinedSwitchString(const std::string switch_key) {
+#if defined(OS_WIN)
+  return ASCIIToUTF16(switch_key);
+#elif defined(OS_POSIX)
+  return switch_key;
+#endif
+}
+
 }  // namespace
 
 CommandLine::CommandLine(NoProgram no_program)
@@ -334,13 +351,8 @@ void CommandLine::AppendSwitchPath(const std::string& switch_string,
 
 void CommandLine::AppendSwitchNative(const std::string& switch_string,
                                      const CommandLine::StringType& value) {
-#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
+  const std::string switch_key = GetSwitchKey(switch_string);
+  StringType combined_switch_string = GetCombinedSwitchString(switch_key);
   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
   auto insertion =
       switches_.insert(make_pair(switch_key.substr(prefix_length), value));
@@ -365,6 +377,20 @@ void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 #endif
 }
 
+void CommandLine::RemoveSwitchForTesting(const std::string& switch_string) {
+  const std::string switch_key = GetSwitchKey(switch_string);
+  StringType combined_switch_string = GetCombinedSwitchString(switch_key);
+  size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
+  switches_by_stringpiece_.erase(switch_key.substr(prefix_length));
+  switches_.erase(switch_string.substr(prefix_length));
+
+  auto find_switch = [&combined_switch_string](const std::string& argv_entry) {
+    return argv_entry.find(combined_switch_string) != std::string::npos;
+  };
+
+  base::EraseIf(argv_, find_switch);
+}
+
 void CommandLine::CopySwitchesFrom(const CommandLine& source,
                                    const char* const switches[],
                                    size_t count) {