Restart Chrome if per session flags have been specified on ChromeOS.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 10c25401118f20caa5740153e07fe44c2e6e0904..cf2d56f53d24fedafe094e12740dd2de367e4c5f 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -40,6 +40,7 @@
 
 #if defined(OS_CHROMEOS)
 #include "chromeos/chromeos_switches.h"
+#include "third_party/cros_system_api/switches/chrome_switches.h"
 #endif
 
 using content::UserMetricsAction;
@@ -85,6 +86,43 @@ void AddOsStrings(unsigned bitmask, ListValue* list) {
       list->Append(new StringValue(kBitsToOs[i].name));
 }
 
+// Convert switch constants to proper CommandLine::StringType strings.
+CommandLine::StringType GetSwitchString(const std::string& flag) {
+#if defined(OS_WIN)
+  CommandLine::StringType result(L"--");
+  result.append(ASCIIToWide(flag));
+#else
+  CommandLine::StringType result("--");
+  result.append(flag);
+#endif
+  return result;
+}
+
+// Scoops flags from a command line.
+std::set<CommandLine::StringType> ExtractFlagsFromCommandLine(
+    const CommandLine& cmdline) {
+  std::set<CommandLine::StringType> flags;
+  // First do the ones between --flag-switches-begin and --flag-switches-end.
+  CommandLine::StringVector::const_iterator first =
+      std::find(cmdline.argv().begin(), cmdline.argv().end(),
+                GetSwitchString(switches::kFlagSwitchesBegin));
+  CommandLine::StringVector::const_iterator last =
+      std::find(cmdline.argv().begin(), cmdline.argv().end(),
+                GetSwitchString(switches::kFlagSwitchesEnd));
+  if (first != cmdline.argv().end() && last != cmdline.argv().end())
+    flags.insert(first + 1, last);

[Mattias Nissler (ping if slow), 2013/06/13 16:55:57]

if you pass the delimiters as parameters, you can make a separate call for
OS_CHROMEOS. That'd further reduce the size of this function and bring it down
to doing a single well-defined thing. Might be worthwhile, but I don't insist -
your call.

[pastarmovj, 2013/06/13 17:29:36]

I decided that it was not worth it, because it will make each call location more
verbose and in the end it will be harder to understand the call locations than
to grasp why this function has two seemingly similar and easy to follow
constructs.

+#if defined(OS_CHROMEOS)
+  // Then add those between --policy-switches-begin and --policy-switches-end.
+  first = std::find(cmdline.argv().begin(), cmdline.argv().end(),
+                    GetSwitchString(chromeos::switches::kPolicySwitchesBegin));
+  last = std::find(cmdline.argv().begin(), cmdline.argv().end(),
+                   GetSwitchString(chromeos::switches::kPolicySwitchesEnd));
+  if (first != cmdline.argv().end() && last != cmdline.argv().end())
+    flags.insert(first + 1, last);
+#endif
+  return flags;
+}
+
 const Experiment::Choice
     kOmniboxHistoryQuickProviderReorderForInliningChoices[] = {
   { IDS_FLAGS_OMNIBOX_HISTORY_QUICK_PROVIDER_REORDER_FOR_INLINING_AUTOMATIC,
@@ -1758,6 +1796,26 @@ void ConvertFlagsToSwitches(PrefService* prefs, CommandLine* command_line) {
   FlagsState::GetInstance()->ConvertFlagsToSwitches(prefs, command_line);
 }
 
+bool CompareSwitchesToCurrentCommandLine(const CommandLine& new_cmdline,
+                                         const CommandLine& active_cmdline) {
+  std::set<CommandLine::StringType> new_flags =
+      ExtractFlagsFromCommandLine(new_cmdline);
+  std::set<CommandLine::StringType> active_flags =
+      ExtractFlagsFromCommandLine(active_cmdline);
+
+  // Don't even bother comparing if the sizes differ.

[Mattias Nissler (ping if slow), 2013/06/13 16:55:57]

can't you just do this?

std::equal(new_flags.first(), new_flags.last(),
           active_flags.first(), active_flags.last())
                           

[pastarmovj, 2013/06/13 17:29:36]

True, dunno why I got the heavier version here :) Anyway I couldn't get rid of
the size check because the std::equals doesn't check the second list for being
empty if the first is not it will happily deref the *iter2 even if it is end()
:-(

+  if (new_flags.size() != active_flags.size())
+    return false;
+
+  CommandLine::StringVector flags_difference(new_flags.size() +
+                                             active_flags.size());
+  CommandLine::StringVector::iterator last_difference =
+      std::set_symmetric_difference(new_flags.begin(), new_flags.end(),
+                                    active_flags.begin(), active_flags.end(),
+                                    flags_difference.begin());
+  return last_difference == flags_difference.begin();
+}
+
 void GetFlagsExperimentsData(PrefService* prefs,
                              FlagAccess access,
                              base::ListValue* supported_experiments,