Revert 212794 "Migrate users from "WebKit" flag to "Web Platform"."

> Migrate users from "WebKit" flag to "Web Platform".
> 
> We changed the name of the "Experimental WebKit Features" flag, and changed
> the actual flag at the same time[1]. I decided at the time to simply throw away
> the old flag; I've been reliably informed that developers aren't particularly
> thrilled with that decision. "Why have my experimental features stopped
> working?" they ask. "Didn't you read my G+ post?" isn't a particularly helpful
> answer, especially since most people (unbelievably!) don't follow me on
> The Internets™.
> 
> This patch hacks a migration system into about:flags, which I hope we never
> ever have to use again, and can safely throw away after a release cycle or two.
> 
> [1]: https://codereview.chromium.org/14940009/
> 
> R=jochen@chromium.org,thakis@chromium.org
> 
> Review URL: https://chromiumcodereview.appspot.com/19520007

TBR=mkwst@chromium.org

Review URL: https://codereview.chromium.org/19514003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@212828 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 2 insertions, 70 deletions

diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index e239a43..6ca3032 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -309,7 +309,6 @@ const Experiment::Choice kTabCaptureDownscaleQualityChoices[] = {
 //   array of choices.
 // See the documentation of Experiment for details on the fields.
 //
-
 // When adding a new choice, add it to the end of the list.
 const Experiment kExperiments[] = {
   {
@@ -1637,15 +1636,6 @@ const Experiment kExperiments[] = {
 const Experiment* experiments = kExperiments;
 size_t num_experiments = arraysize(kExperiments);
 
-const Migration kMigrations[] = {
-  // TODO(mkwst): Remove this once some reasonable amount of time has passed.
-  {"enable-experimental-webkit-features",
-   "enable-experimental-web-platform-features"}
-};
-
-const Migration* migrations = kMigrations;
-size_t num_migrations = arraysize(kMigrations);
-
 // Stores and encapsulates the little state that about:flags has.
 class FlagsState {
  public:
@@ -1714,17 +1704,6 @@ bool ValidateExperiment(const Experiment& e) {
   return true;
 }
 
-// Given the set of currently active experiments, migrate deprecated experiments
-// to their shiny new counterparts.
-void MigrateExperiments(std::set<std::string>* experimentList) {
-  for (size_t i = 0; i < num_migrations; ++i) {
-    if (experimentList->count(migrations[i].from)) {
-      experimentList->erase(experimentList->find(migrations[i].from));
-      experimentList->insert(migrations[i].to);
-    }
-  }
-}
-
 // Removes all experiments from prefs::kEnabledLabsExperiments that are
 // unknown, to prevent this list to become very long as experiments are added
 // and removed.
@@ -1735,11 +1714,7 @@ void SanitizeList(FlagsStorage* flags_storage) {
     AddInternalName(experiments[i], &known_experiments);
   }
 
-  // Store the original list of Experiments, then copy it for processing.
-  std::set<std::string> unsanitized_experiments = flags_storage->GetFlags();
-  std::set<std::string> enabled_experiments = unsanitized_experiments;
-
-  MigrateExperiments(&enabled_experiments);
+  std::set<std::string> enabled_experiments = flags_storage->GetFlags();
 
   std::set<std::string> new_enabled_experiments;
   std::set_intersection(
@@ -1747,7 +1722,7 @@ void SanitizeList(FlagsStorage* flags_storage) {
       enabled_experiments.begin(), enabled_experiments.end(),
       std::inserter(new_enabled_experiments, new_enabled_experiments.begin()));
 
-  if (new_enabled_experiments != unsanitized_experiments)
+  if (new_enabled_experiments != enabled_experiments)
     flags_storage->SetFlags(new_enabled_experiments);
 }
 
@@ -2139,16 +2114,6 @@ void SetExperiments(const Experiment* e, size_t count) {
   }
 }
 
-void SetMigrations(const Migration* e, size_t count) {
-  if (!e) {
-    migrations = kMigrations;
-    num_migrations = arraysize(kMigrations);
-  } else {
-    migrations = e;
-    num_migrations = count;
-  }
-}
-
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
diff --git a/chrome/browser/about_flags.h b/chrome/browser/about_flags.h
index c7fdc53..5d67e97 100644
--- a/chrome/browser/about_flags.h
+++ b/chrome/browser/about_flags.h
@@ -105,13 +105,6 @@ struct Experiment {
   string16 DescriptionForChoice(int index) const;
 };
 
-// Migration is used internally by about_flags to move users from old,
-// busted flags to the new hotness. This is exposed only for testing.
-struct Migration {
-  const char* const from;
-  const char* const to;
-};
-
 // Reads the Labs |prefs| (called "Labs" for historical reasons) and adds the
 // commandline flags belonging to the active experiments to |command_line|.
 void ConvertFlagsToSwitches(FlagsStorage* flags_storage,
@@ -170,10 +163,6 @@ void ClearState();
 // NOT take ownership of the supplied Experiments.
 void SetExperiments(const Experiment* e, size_t count);
 
-// Sets the list of migrations. Pass in NULL to use the default set. This does
-// NOT take ownership of the supplied Migrations.
-void SetMigrations(const Migration* e, size_t count);
-
 // Returns the current set of experiments.
 const Experiment* GetExperiments(size_t* count);
 
diff --git a/chrome/browser/about_flags_unittest.cc b/chrome/browser/about_flags_unittest.cc
index 3d9fbd2..34219c3 100644
--- a/chrome/browser/about_flags_unittest.cc
+++ b/chrome/browser/about_flags_unittest.cc
@@ -110,13 +110,6 @@ static Experiment kExperiments[] = {
   },
 };
 
-static Migration kMigrations[] = {
-  {
-    kFlags1,
-    kFlags2
-  }
-};
-
 class AboutFlagsTest : public ::testing::Test {
  protected:
   AboutFlagsTest() : flags_storage_(&prefs_) {
@@ -230,21 +223,6 @@ TEST_F(AboutFlagsTest, ConvertFlagsToSwitches) {
   EXPECT_TRUE(command_line.HasSwitch(kSwitch1));
 }
 
-TEST_F(AboutFlagsTest, ConvertFlagsToSwitchesMigration) {
-  testing::SetMigrations(kMigrations, arraysize(kMigrations));
-  SetExperimentEnabled(&flags_storage_,kFlags1, true);
-
-  CommandLine command_line(CommandLine::NO_PROGRAM);
-
-  EXPECT_FALSE(command_line.HasSwitch(kSwitch1));
-  EXPECT_FALSE(command_line.HasSwitch(kSwitch2));
-
-  ConvertFlagsToSwitches(&flags_storage_, &command_line);
-
-  EXPECT_FALSE(command_line.HasSwitch(kSwitch1));
-  EXPECT_TRUE(command_line.HasSwitch(kSwitch2));
-}
-
 TEST_F(AboutFlagsTest, CompareSwitchesToCurrentCommandLine) {
   SetExperimentEnabled(&flags_storage_, kFlags1, true);