[Dynamic Refresh] Guard behind a feature flag

BUG=881371,737995
R=sky,robliao

Change-Id: I9798f20415975c7f98528b2f746aaffe6a66af1e
Reviewed-on: https://chromium-review.googlesource.com/c/1316834
Commit-Queue: Robert Liao <robliao@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609065}

ui/base/material_design/material_design_controller.cc

@@ -65,7 +65,8 @@ void MaterialDesignController::Initialize() {
 
   // When the mode is not explicitly forced, platforms vary as to the default
   // behavior.
-  if (!touch && (switch_value != switches::kTopChromeTouchUiDisabled)) {
+  if (!touch && (switch_value != switches::kTopChromeTouchUiDisabled) &&
+      features::IsAutomaticUiAdjustmentsForTouchEnabled()) {
 #if defined(OS_CHROMEOS)
     // TabletModeClient's default state is in non-tablet mode.
     automatic_touch_ui_ = true;

ui/base/ui_base_features.cc

@@ -120,6 +120,11 @@ const base::Feature kPrecisionTouchpadScrollPhase{
     "PrecisionTouchpadScrollPhase", base::FEATURE_ENABLED_BY_DEFAULT};
 #endif  // defined(OS_WIN)
 
+#if defined(OS_WIN) || defined(OS_CHROMEOS)
+const base::Feature kEnableAutomaticUiAdjustmentsForTouch{
+    "EnableAutomaticUiAdjustmentsForTouch", base::FEATURE_ENABLED_BY_DEFAULT};
+#endif  // defined(OS_WIN) || defined(OS_CHROMEOS)
+
 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
 // Enables stylus appearing as touch when in contact with digitizer.
 const base::Feature kDirectManipulationStylus = {
@@ -149,6 +154,15 @@ bool IsSingleProcessMash() {
   return base::FeatureList::IsEnabled(features::kSingleProcessMash);
 }
 
+bool IsAutomaticUiAdjustmentsForTouchEnabled() {
+#if defined(OS_WIN) || defined(OS_CHROMEOS)
+  return base::FeatureList::IsEnabled(
+      features::kEnableAutomaticUiAdjustmentsForTouch);
+#else
+  return false;
+#endif
+}
+
 #if defined(OS_MACOSX)
 // When enabled, the NSWindows for apps will be created in the app's process,
 // and will forward input to the browser process.

ui/base/ui_base_features.h

@@ -43,6 +43,10 @@ UI_BASE_EXPORT extern const base::Feature kTSFImeSupport;
 UI_BASE_EXPORT bool IsUsingWMPointerForTouch();
 #endif  // defined(OS_WIN)
 
+#if defined(OS_WIN) || defined(OS_CHROMEOS)
+UI_BASE_EXPORT extern const base::Feature kEnableAutomaticUiAdjustmentsForTouch;
+#endif  // defined(OS_WIN) || defined(OS_CHROMEOS)
+
 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
 UI_BASE_EXPORT extern const base::Feature kDirectManipulationStylus;
 #endif  // defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
@@ -68,6 +72,9 @@ UI_BASE_EXPORT bool IsMultiProcessMash();
 // See //ash/README.md.
 UI_BASE_EXPORT bool IsSingleProcessMash();
 
+// Whether the UI may accommodate touch input in response to hardware changes.
+UI_BASE_EXPORT bool IsAutomaticUiAdjustmentsForTouchEnabled();
+
 #if defined(OS_MACOSX)
 UI_BASE_EXPORT extern const base::Feature kHostWindowsInAppShimProcess;