gzip chrome://tracing resources.

Compiling locally, resources.pak goes from 16744913 bytes to 14952341
(nearly 1.8MiB savings).

Review-Url: https://codereview.chromium.org/2933483005
Cr-Commit-Position: refs/heads/master@{#478678}

content/browser/tracing/generate_trace_viewer_grd.py

@@ -58,6 +58,7 @@ def add_file_to_grd(grd_doc, filename):
   new_include_node.setAttribute('name', make_name_from_filename(filename))
   new_include_node.setAttribute('file', filename)
   new_include_node.setAttribute('type', 'BINDATA')
+  new_include_node.setAttribute('compress', 'gzip')
   new_include_node.setAttribute('flattenhtml', 'true')
   if filename.endswith('.html'):
     new_include_node.setAttribute('allowexternalscript', 'true')

content/browser/tracing/tracing_ui.cc

@@ -240,6 +240,13 @@ TracingUI::TracingUI(WebUI* web_ui)
       web_ui->GetWebContents()->GetBrowserContext();
 
   WebUIDataSource* source = WebUIDataSource::Create(kChromeUITracingHost);
+  std::unordered_set<std::string> exclusions;
+  exclusions.insert("json/begin_recording");
+  exclusions.insert("json/categories");
+  exclusions.insert("json/end_recording_compressed");
+  exclusions.insert("json/get_buffer_percent_full");
+  exclusions.insert("json/get_buffer_status");
+  source->UseGzip(exclusions);
   source->SetJsonPath("strings.js");
   source->SetDefaultResource(IDR_TRACING_HTML);
   source->AddResourcePath("tracing.js", IDR_TRACING_JS);