[ObsUX][Profiling] Remove float numbers on samples (#211489)

Closes https://github.com/elastic/kibana/issues/181295

#### Summary

There should be no decimal / fraction in the number of samples (those
are integer values).

#### What was done

When the scale factor was a number with decimals, was changing the value
of the samples to a float number
Also, the background color for the `Normalized By` dropdown was fixed in
dark mode

Before

<img width="1335" alt="image"
src="https://github.com/user-attachments/assets/93b6c301-5b7f-41b6-857b-3551cf88b095"
/>

After

<img width="1335" alt="image"
src="https://github.com/user-attachments/assets/ebbe78ed-d8cb-4308-acf4-0d15221f986b"
/>

x-pack/solutions/observability/plugins/profiling/public/components/frames_summary/index.tsx

@@ -18,7 +18,7 @@ import { isEmpty } from 'lodash';
 import React, { useMemo } from 'react';
 import { asCost } from '../../utils/formatters/as_cost';
 import { asWeight } from '../../utils/formatters/as_weight';
-import { calculateBaseComparisonDiff } from '../topn_functions/utils';
+import { calculateBaseComparisonDiff, scaleAndRoundValue } from '../topn_functions/utils';
 import { SummaryItem } from './summary_item';
 
 interface FrameValue {
@@ -40,10 +40,6 @@ const ESTIMATED_VALUE_LABEL = i18n.translate('xpack.profiling.diffTopNFunctions.
   defaultMessage: 'Estimated value',
 }) as string;
 
-function getScaleFactor(scaleFactor: number = 1) {
-  return scaleFactor;
-}
-
 export function FramesSummary({
   baseValue,
   comparisonValue,
@@ -52,11 +48,14 @@ export function FramesSummary({
   compressed = false,
 }: Props) {
   const baselineScaledTotalSamples = baseValue
-    ? baseValue.totalCount * getScaleFactor(baseValue.scaleFactor)
+    ? scaleAndRoundValue({ value: baseValue.totalCount, scaleFactor: baseValue.scaleFactor })
     : 0;
 
   const comparisonScaledTotalSamples = comparisonValue
-    ? comparisonValue.totalCount * getScaleFactor(comparisonValue.scaleFactor)
+    ? scaleAndRoundValue({
+        value: comparisonValue.totalCount,
+        scaleFactor: comparisonValue.scaleFactor,
+      })
     : 0;
 
   const { co2EmissionDiff, costImpactDiff, totalSamplesDiff } = useMemo(() => {

x-pack/solutions/observability/plugins/profiling/public/components/normalization_menu/index.tsx

@@ -113,7 +113,7 @@ export function NormalizationMenu(props: Props) {
             style={{
               height: '100%',
               justifyContent: 'center',
-              backgroundColor: theme.euiTheme.colors.ghost,
+              backgroundColor: theme.euiTheme.colors.backgroundBasePlain,
               padding: '0 16px',
             }}
           >

x-pack/solutions/observability/plugins/profiling/public/components/topn_functions/total_samples_stat.tsx

@@ -9,7 +9,7 @@ import { EuiStat, EuiText } from '@elastic/eui';
 import { i18n } from '@kbn/i18n';
 import React from 'react';
 import { Label } from './label';
-import { scaleValue } from './utils';
+import { scaleAndRoundValue } from './utils';
 
 interface Props {
   baselineTotalSamples: number;
@@ -24,7 +24,7 @@ export function TotalSamplesStat({
   comparisonTotalSamples,
   comparisonScaleFactor,
 }: Props) {
-  const scaledBaselineTotalSamples = scaleValue({
+  const scaledBaselineTotalSamples = scaleAndRoundValue({
     value: baselineTotalSamples,
     scaleFactor: baselineScaleFactor,
   });
@@ -44,7 +44,7 @@ export function TotalSamplesStat({
     );
   }
 
-  const scaledComparisonTotalSamples = scaleValue({
+  const scaledComparisonTotalSamples = scaleAndRoundValue({
     value: comparisonTotalSamples,
     scaleFactor: comparisonScaleFactor,
   });

x-pack/solutions/observability/plugins/profiling/public/components/topn_functions/utils.ts

@@ -32,10 +32,20 @@ export function getColorLabel(percent: number) {
   return { color: 'text', label: undefined, icon: undefined };
 }
 
-export function scaleValue({ value, scaleFactor = 1 }: { value: number; scaleFactor?: number }) {
+function scaleValue({ value, scaleFactor = 1 }: { value: number; scaleFactor?: number }) {
   return value * scaleFactor;
 }
 
+export function scaleAndRoundValue({
+  value,
+  scaleFactor = 1,
+}: {
+  value: number;
+  scaleFactor?: number;
+}) {
+  return Math.round(scaleValue({ value, scaleFactor }));
+}
+
 export const getTotalCount = (topNFunctions?: TopNFunctions) => topNFunctions?.selfCPU ?? 0;
 
 export interface IFunctionRow {