Enabled Screen Rotation Animations.

Removed the "slow" animation variants and created a "default" switch value which
is set to the partial rotation animation.

TEST=Manually verified the animations worked for each of the switch values.

BUG=337596

Review URL: https://codereview.chromium.org/1044263003

Cr-Commit-Position: refs/heads/master@{#323493}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index b2323fb2..75833e5 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -396,15 +396,16 @@
 
 #if defined(USE_ASH)
 const Experiment::Choice kAshScreenRotationAnimationChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    ash::switches::kAshEnableScreenRotationAnimation,
+    "none" },
   { IDS_ASH_SCREEN_ROTATION_ANIMATION_PARTIAL_ROTATION,
-    ash::switches::kAshEnableScreenRotationAnimation, "partial-rotation" },
-  { IDS_ASH_SCREEN_ROTATION_ANIMATION_PARTIAL_ROTATION_SLOW,
-    ash::switches::kAshEnableScreenRotationAnimation, "partial-rotation-slow" },
+    ash::switches::kAshEnableScreenRotationAnimation,
+    "partial-rotation" },
   { IDS_ASH_SCREEN_ROTATION_ANIMATION_FULL_ROTATION,
-    ash::switches::kAshEnableScreenRotationAnimation, "full-rotation" },
-  { IDS_ASH_SCREEN_ROTATION_ANIMATION_FULL_ROTATION_SLOW,
-    ash::switches::kAshEnableScreenRotationAnimation, "full-rotation-slow" }
+    ash::switches::kAshEnableScreenRotationAnimation,
+    "full-rotation" }
 };
 #endif