Initial patch set to implement improved touch support for screen magnification

chrome/browser/about_flags.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 2161 matching lines @@
      kOsAndroid, FEATURE_WITH_VARIATIONS_VALUE_TYPE(
                      autofill::kAutofillCreditCardPopupLayout,
                      kAutofillCreditCardPopupLayoutFeatureVariations,
                      "AutofillCreditCardPopupLayout")},
     {"native-android-history-manager", IDS_NATIVE_ANDROID_HISTORY_MANAGER,
      IDS_NATIVE_ANDROID_HISTORY_MANAGER_DESCRIPTION, kOsAndroid,
      FEATURE_VALUE_TYPE(chrome::android::kNativeAndroidHistoryManager)},
 #endif  // OS_ANDROID
     {"enable-faster-location-reload", IDS_FLAGS_FASTER_LOCATION_RELOAD_NAME,
      IDS_FLAGS_FASTER_LOCATION_RELOAD_DESCRIPTION, kOsAll,
-     FEATURE_VALUE_TYPE(features::kFasterLocationReload)}
+     FEATURE_VALUE_TYPE(features::kFasterLocationReload)},
+#if defined(OS_CHROMEOS)
+    {"enable-touch-support-for-screen-magnification",

[yoshiki, 2017/01/20 05:26:33]

Optional: The feature name is "screen magnifier", so I think
"for-screen-magnifier" is better. But the decision is up to you.

[yawano, 2017/02/06 06:49:04]

Done.

+     IDS_FLAGS_ENABLE_TOUCH_SUPPORT_FOR_SCREEN_MAGNIFICATION_NAME,
+     IDS_FLAGS_ENABLE_TOUCH_SUPPORT_FOR_SCREEN_MAGNIFICATION_DESCRIPTION,
+     kOsCrOS,
+     SINGLE_VALUE_TYPE(
+         chromeos::switches::kEnableTouchSupportForScreenMagnification)}
+#endif  // OS_CHROMEOS
 
     // NOTE: Adding new command-line switches requires adding corresponding
     // entries to enum "LoginCustomFlags" in histograms.xml. See note in
     // histograms.xml and don't forget to run AboutFlagsHistogramTest unit test.
 };
 
 class FlagsStateSingleton {
  public:
   FlagsStateSingleton()
       : flags_state_(kFeatureEntries, arraysize(kFeatureEntries)) {}
@@ skipping 189 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags