Tweak strings used for CPU calibration.

Bug: 311438112
Change-Id: I804e2ac64e6d31c3b30e9e855d84f80444935fc1
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6168379
Commit-Queue: Connor Clark <[email protected]>
Reviewed-by: Paul Irish <[email protected]>

Author: Connor Clark

front_end/panels/mobile_throttling/ThrottlingSettingsTab.ts

@@ -143,12 +143,16 @@ const UIStrings = {
    * @description Text to use to indicate that a CPU calibration has not been run yet.
    */
   needsCalibration: 'Needs calibration',
-  // TODO(crbug.com/311438112): Add 'Learn more' link.
   /**
    *@description Text to explain why the user should run the CPU calibration process.
    */
   calibrationCTA:
       'To use the CPU throttling presets, run the calibration process to determine the ideal throttling rate for your device.',
+  /**
+   *@description Text to explain what CPU throttling presets are.
+   */
+  cpuCalibrationDescription:
+      'These presets throttle your CPU to approximate the performance of typical low or mid-tier mobile devices.',
   /**
    *@description Text to explain how the CPU calibration process will work.
    */
@@ -218,6 +222,9 @@ export class CPUThrottlingCard {
 
     const card = new Cards.Card.Card();
 
+    const descriptionEl = card.createChild('span');
+    descriptionEl.textContent = i18nString(UIStrings.cpuCalibrationDescription);
+
     this.lowTierMobileDeviceEl = card.createChild('div', 'cpu-preset-section');
     this.lowTierMobileDeviceEl.append('Low-tier mobile device');
     this.lowTierMobileDeviceEl.createChild('div', 'cpu-preset-result');
@@ -256,7 +263,7 @@ export class CPUThrottlingCard {
 
     card.data = {
       heading: i18nString(UIStrings.cpuThrottlingPresets),
-      content: [this.lowTierMobileDeviceEl, this.midTierMobileDeviceEl, this.calibrateEl],
+      content: [descriptionEl, this.lowTierMobileDeviceEl, this.midTierMobileDeviceEl, this.calibrateEl],
     };
     this.element = card;
 
@@ -294,9 +301,11 @@ export class CPUThrottlingCard {
       this.calibrateButton.textContent =
           hasCalibrated ? i18nString(UIStrings.recalibrate) : i18nString(UIStrings.calibrate);
 
-      this.textEl.style.display = '';
-      this.textEl.textContent = '';
-      this.textEl.append(this.createTextWithIcon(i18nString(UIStrings.calibrationCTA), 'info'));
+      if (!hasCalibrated) {
+        this.textEl.style.display = '';
+        this.textEl.textContent = '';
+        this.textEl.append(this.createTextWithIcon(i18nString(UIStrings.calibrationCTA), 'info'));
+      }
     } else if (this.state === 'prompting') {
       this.calibrateButton.style.display = '';
       this.calibrateButton.textContent = i18nString(UIStrings.continue);