feat(perf-issues): Replace sentence style keys with snake case

Replaces old sentence style keys being used for browser spans with
snake case equivalents.

Author: narsaynorath

packages/replay/test/fixtures/transaction.ts

@@ -74,9 +74,9 @@ export function Transaction(traceId?: string, obj?: Partial<Event>): any {
       },
       {
         data: {
-          'Transfer Size': 1097,
-          'Encoded Body Size': 797,
-          'Decoded Body Size': 1885,
+          'http.transfer_size': 1097,
+          'http.response_content_length': 797,
+          'http.decoded_response_content_length': 1885,
           'resource.render_blocking_status': 'non-blocking',
         },
         description: '/favicon.ico',

packages/tracing-internal/src/browser/metrics/index.ts

@@ -402,13 +402,13 @@ export function _addResourceSpans(
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const data: Record<string, any> = {};
   if ('transferSize' in entry) {
-    data['Transfer Size'] = entry.transferSize;
+    data['http.transfer_size'] = entry.transferSize;
   }
   if ('encodedBodySize' in entry) {
-    data['Encoded Body Size'] = entry.encodedBodySize;
+    data['http.response_content_length'] = entry.encodedBodySize;
   }
   if ('decodedBodySize' in entry) {
-    data['Decoded Body Size'] = entry.decodedBodySize;
+    data['http.decoded_response_content_length'] = entry.decodedBodySize;
   }
   if ('renderBlockingStatus' in entry) {
     data['resource.render_blocking_status'] = entry.renderBlockingStatus;

packages/tracing-internal/test/browser/metrics/index.test.ts

@@ -90,9 +90,9 @@ describe('_addResourceSpans', () => {
     // eslint-disable-next-line @typescript-eslint/unbound-method
     expect(transaction.startChild).toHaveBeenLastCalledWith({
       data: {
-        ['Decoded Body Size']: entry.decodedBodySize,
-        ['Encoded Body Size']: entry.encodedBodySize,
-        ['Transfer Size']: entry.transferSize,
+        ['http.decoded_response_content_length']: entry.decodedBodySize,
+        ['http.response_content_length']: entry.encodedBodySize,
+        ['http.transfer_size']: entry.transferSize,
         ['resource.render_blocking_status']: entry.renderBlockingStatus,
       },
       description: '/assets/to/css',
@@ -158,9 +158,9 @@ describe('_addResourceSpans', () => {
     expect(transaction.startChild).toHaveBeenLastCalledWith(
       expect.objectContaining({
         data: {
-          ['Decoded Body Size']: entry.decodedBodySize,
-          ['Encoded Body Size']: entry.encodedBodySize,
-          ['Transfer Size']: entry.transferSize,
+          ['http.decoded_response_content_length']: entry.decodedBodySize,
+          ['http.response_content_length']: entry.encodedBodySize,
+          ['http.transfer_size']: entry.transferSize,
           ['resource.render_blocking_status']: entry.renderBlockingStatus,
         },
       }),