Misc. cleanup, chromecast/ edition.

* TimeDelta::InMicrosecondsF() actually returns a double
* Shorten code

Bug: none
Change-Id: I0dc35be9c2298e79d8a8f0cd34492d09c04cf9c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2359002
Commit-Queue: Sergey Volk <servolk@chromium.org>
Reviewed-by: Sergey Volk <servolk@chromium.org>
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798478}

chromecast/base/metrics/cast_metrics_helper.cc

@@ -294,7 +294,7 @@ void CastMetricsHelper::LogMediumTimeHistogramEvent(const std::string& name,
 base::Value CastMetricsHelper::CreateEventBase(const std::string& name) {
   base::Value cast_event(base::Value::Type::DICTIONARY);
   cast_event.SetKey("name", base::Value(name));
-  const double time = (Now() - base::TimeTicks()).InMicroseconds();
+  const double time = (Now() - base::TimeTicks()).InMicrosecondsF();
   cast_event.SetKey("time", base::Value(time));
   return cast_event;
 }

chromecast/graphics/accessibility/accessibility_focus_ring_controller.cc

@@ -435,10 +435,8 @@ void AccessibilityFocusRingController::AnimateFocusRings(
       return;
     }
 
-    double fraction = delta / transition_time;
-
     // Ease-in effect.
-    fraction = pow(fraction, 0.3);
+    const double fraction = pow(delta / transition_time, 0.3);
 
     // Handle corner case where we're animating but we don't have previous
     // rings.
@@ -480,9 +478,7 @@ void AccessibilityFocusRingController::ComputeOpacity(
     opacity = 1.0 - (change_delta / (fade_in_time + fade_out_time));
 
   // Layer::SetOpacity will throw an error if we're not within 0...1.
-  opacity = base::ClampToRange(opacity, 0.0f, 1.0f);
-
-  animation_info->opacity = opacity;
+  animation_info->opacity = base::ClampToRange(opacity, 0.0f, 1.0f);
 }
 
 void AccessibilityFocusRingController::AnimateCaretRing(