Add throbber and status text to WebBluetooth chooser UI on non-Mac desktops

chrome/browser/chooser_controller/mock_chooser_controller.cc

Index: chrome/browser/chooser_controller/mock_chooser_controller.cc
diff --git a/chrome/browser/chooser_controller/mock_chooser_controller.cc b/chrome/browser/chooser_controller/mock_chooser_controller.cc
index e585addc0e37752911cd197fa714fed54bb2b501..0b5be9e9f87769d066101321c8793cb78915efe1 100644
--- a/chrome/browser/chooser_controller/mock_chooser_controller.cc
+++ b/chrome/browser/chooser_controller/mock_chooser_controller.cc
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include "chrome/browser/chooser_controller/mock_chooser_controller.h"
+
 #include "chrome/grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
 
 MockChooserController::MockChooserController(content::RenderFrameHost* owner)
     : ChooserController(owner,
@@ -12,6 +14,10 @@ MockChooserController::MockChooserController(content::RenderFrameHost* owner)
 
 MockChooserController::~MockChooserController() {}
 
+base::string16 MockChooserController::GetNoOptionsText() const {
+  return l10n_util::GetStringUTF16(IDS_DEVICE_CHOOSER_NO_DEVICES_FOUND_PROMPT);

[msw, 2016/07/18 23:01:30]

Could the mock return an empty string like GetStatus?

[juncai, 2016/07/19 20:42:45]

It could, but the unit test needs to check what is shown on the table view when
there are no devices:
https://cs.chromium.org/chromium/src/chrome/browser/ui/views/chooser_content_...

Also maybe it is better to use a string literal in the unit test instead of
using IDS_DEVICE_CHOOSER_NO_DEVICES_FOUND_PROMPT? Just in case the
IDS_DEVICE_CHOOSER_NO_DEVICES_FOUND_PROMPT is accidentally modified. I made the
changes in chooser_content_view_unittest.cc.

[msw, 2016/07/19 22:08:10]

I don't think it's a good idea to use a string literal in the test. That's
basically a change detector test. Using
IDS_DEVICE_CHOOSER_NO_DEVICES_FOUND_PROMPT here is fine.

[juncai, 2016/07/19 22:58:24]

Done.

+}
+
 base::string16 MockChooserController::GetOkButtonLabel() const {
   return base::string16();
 }
@@ -24,6 +30,12 @@ base::string16 MockChooserController::GetOption(size_t index) const {
   return option_names_[index];
 }
 
+void MockChooserController::RefreshOptions() {}
+
+base::string16 MockChooserController::GetStatus() const {
+  return base::string16();
+}
+
 void MockChooserController::OptionAdded(const base::string16 option_name) {
   option_names_.push_back(option_name);
   if (observer())