Add ChromeVox panel and implement caption display functionality.

chrome/browser/resources/chromeos/chromevox/BUILD.gn

Index: chrome/browser/resources/chromeos/chromevox/BUILD.gn
diff --git a/chrome/browser/resources/chromeos/chromevox/BUILD.gn b/chrome/browser/resources/chromeos/chromevox/BUILD.gn
index 105a1dbde8e917d5a1291d4b426491767819e0c2..86ff28e38507b3b8821cd8f4603b2e467a8d0909 100644
--- a/chrome/browser/resources/chromeos/chromevox/BUILD.gn
+++ b/chrome/browser/resources/chromeos/chromevox/BUILD.gn
@@ -35,6 +35,7 @@ group("chromevox") {
       ":chromevox1_kbexplorer_script",
       ":chromevox1_options_script",
       ":chromevox2_background_script",
+      ":chromevox2_panel_script",
     ]
   } else {
     deps += [ ":chromevox_deps_js" ]
@@ -148,6 +149,7 @@ run_jsbundler("chromevox_copied_files") {
     "chromevox/background/options.html",
     "chromevox/injected/api.js",
     "cvox2/background/background.html",
+    "cvox2/background/panel.html",
   ]
   if (chromevox_compress_js) {
     sources += [ "chromevox/injected/api_util.js" ]
@@ -159,6 +161,7 @@ run_jsbundler("chromevox_copied_files") {
       chromevox_vars_gypi_values.chromevox1_kbexplorer_loader_file,
       chromevox_vars_gypi_values.chromevox1_options_script_loader_file,
       chromevox_vars_gypi_values.chromevox2_background_script_loader_file,
+      chromevox_vars_gypi_values.chromevox2_panel_script_loader_file,
     ]
   }
   if (!chromevox_compress_js) {
@@ -283,6 +286,13 @@ if (chromevox_compress_js) {
     ]
     output_file = "$chromevox_out_dir/chromeVox2ChromeBackgroundScript.js"
   }
+
+  compress_js("chromevox2_panel_script") {
+    sources = [
+      chromevox_vars_gypi_values.chromevox2_panel_script_loader_file,
+    ]
+    output_file = "$chromevox_out_dir/chromeVoxPanelScript.js"
+  }
 } else {
   generate_deps_js("chromevox_deps_js") {
     sources = chromevox_modules + closure_library_modules