Update the device permissions prompt when the device list changes.

extensions/browser/api/device_permissions_prompt.cc

Index: extensions/browser/api/device_permissions_prompt.cc
diff --git a/extensions/browser/api/device_permissions_prompt.cc b/extensions/browser/api/device_permissions_prompt.cc
index 8ae677664155e5e399de34eb3085a12d1cfe0ce2..afb895cd642490596df8e226c8f8c4ef25c512a2 100644
--- a/extensions/browser/api/device_permissions_prompt.cc
+++ b/extensions/browser/api/device_permissions_prompt.cc
@@ -17,23 +17,53 @@
 #include "extensions/strings/grit/extensions_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 
-namespace extensions {
-
 using device::UsbDevice;
 using device::UsbDeviceFilter;
 using device::UsbService;
 
+namespace extensions {
+
 DevicePermissionsPrompt::Prompt::DeviceInfo::DeviceInfo(
-    scoped_refptr<UsbDevice> device,
-    const base::string16& name,
-    const base::string16& product_string,
-    const base::string16& manufacturer_string,
-    const base::string16& serial_number)
-    : device(device),
-      name(name),
-      product_string(product_string),
-      manufacturer_string(manufacturer_string),
-      serial_number(serial_number) {
+    scoped_refptr<UsbDevice> device)
+    : device(device) {
+  base::string16 manufacturer_string;
+  if (device->GetManufacturer(&manufacturer_string)) {
+    original_manufacturer_string = manufacturer_string;
+  } else {
+    const char* vendor_name =
+        device::UsbIds::GetVendorName(device->vendor_id());
+    if (vendor_name) {
+      manufacturer_string = base::UTF8ToUTF16(vendor_name);
+    } else {
+      base::string16 vendor_id =
+          base::ASCIIToUTF16(base::StringPrintf("0x%04x", device->vendor_id()));
+      manufacturer_string =
+          l10n_util::GetStringFUTF16(IDS_DEVICE_UNKNOWN_VENDOR, vendor_id);
+    }
+  }
+
+  base::string16 product_string;
+  if (device->GetProduct(&product_string)) {
+    original_product_string = product_string;
+  } else {
+    const char* product_name = device::UsbIds::GetProductName(
+        device->vendor_id(), device->product_id());
+    if (product_name) {
+      product_string = base::UTF8ToUTF16(product_name);
+    } else {
+      base::string16 product_id = base::ASCIIToUTF16(
+          base::StringPrintf("0x%04x", device->product_id()));
+      product_string =
+          l10n_util::GetStringFUTF16(IDS_DEVICE_UNKNOWN_PRODUCT, product_id);
+    }
+  }
+
+  if (!device->GetSerialNumber(&serial_number)) {
+    serial_number.clear();
+  }
+
+  name = l10n_util::GetStringFUTF16(IDS_DEVICE_PERMISSIONS_DEVICE_NAME,
+                                    product_string, manufacturer_string);
 }
 
 DevicePermissionsPrompt::Prompt::DeviceInfo::~DeviceInfo() {
@@ -43,16 +73,18 @@ DevicePermissionsPrompt::Prompt::Prompt()
     : extension_(nullptr),
       browser_context_(nullptr),
       multiple_(false),
-      observer_(nullptr) {
+      observer_(nullptr),
+      usb_service_observer_(this) {
 }
 
 void DevicePermissionsPrompt::Prompt::SetObserver(Observer* observer) {
   observer_ = observer;
 
-  content::BrowserThread::PostTask(
-      content::BrowserThread::FILE,
-      FROM_HERE,
-      base::Bind(&DevicePermissionsPrompt::Prompt::DoDeviceQuery, this));
+  if (observer_) {
+    content::BrowserThread::PostTask(
+        content::BrowserThread::FILE, FROM_HERE,
+        base::Bind(&DevicePermissionsPrompt::Prompt::DoDeviceQuery, this));
+  }
 }
 
 base::string16 DevicePermissionsPrompt::Prompt::GetHeading() const {
@@ -81,11 +113,9 @@ void DevicePermissionsPrompt::Prompt::GrantDevicePermission(
       DevicePermissionsManager::Get(browser_context_);
   if (permissions_manager) {
     const DeviceInfo& device = devices_[index];
-    permissions_manager->AllowUsbDevice(extension_->id(),
-                                        device.device,
-                                        device.product_string,
-                                        device.manufacturer_string,
-                                        device.serial_number);
+    permissions_manager->AllowUsbDevice(
+        extension_->id(), device.device, device.original_product_string,
+        device.original_manufacturer_string, device.serial_number);
   }
 }
 
@@ -112,53 +142,11 @@ void DevicePermissionsPrompt::Prompt::DoDeviceQuery() {
       continue;
     }
 
-    base::string16 manufacturer_string;
-    base::string16 original_manufacturer_string;
-    if (device->GetManufacturer(&original_manufacturer_string)) {
-      manufacturer_string = original_manufacturer_string;
-    } else {
-      const char* vendor_name =
-          device::UsbIds::GetVendorName(device->vendor_id());
-      if (vendor_name) {
-        manufacturer_string = base::UTF8ToUTF16(vendor_name);
-      } else {
-        base::string16 vendor_id = base::ASCIIToUTF16(
-            base::StringPrintf("0x%04x", device->vendor_id()));
-        manufacturer_string =
-            l10n_util::GetStringFUTF16(IDS_DEVICE_UNKNOWN_VENDOR, vendor_id);
-      }
-    }
-
-    base::string16 product_string;
-    base::string16 original_product_string;
-    if (device->GetProduct(&original_product_string)) {
-      product_string = original_product_string;
-    } else {
-      const char* product_name = device::UsbIds::GetProductName(
-          device->vendor_id(), device->product_id());
-      if (product_name) {
-        product_string = base::UTF8ToUTF16(product_name);
-      } else {
-        base::string16 product_id = base::ASCIIToUTF16(
-            base::StringPrintf("0x%04x", device->product_id()));
-        product_string =
-            l10n_util::GetStringFUTF16(IDS_DEVICE_UNKNOWN_PRODUCT, product_id);
-      }
-    }
-
-    base::string16 serial_number;
-    if (!device->GetSerialNumber(&serial_number)) {
-      serial_number.clear();
-    }
+    device_info.push_back(DeviceInfo(device));
+  }
 
-    device_info.push_back(DeviceInfo(
-        device,
-        l10n_util::GetStringFUTF16(IDS_DEVICE_PERMISSIONS_DEVICE_NAME,
-                                   product_string,
-                                   manufacturer_string),
-        original_product_string,
-        original_manufacturer_string,
-        serial_number));
+  if (!usb_service_observer_.IsObserving(service)) {
+    usb_service_observer_.Add(service);
   }
 
   content::BrowserThread::PostTask(
@@ -176,6 +164,48 @@ void DevicePermissionsPrompt::Prompt::SetDevices(
   }
 }
 
+void DevicePermissionsPrompt::Prompt::AddDevice(const DeviceInfo& device) {
+  devices_.push_back(device);
+  if (observer_) {
+    observer_->OnDevicesChanged();
+  }
+}
+
+void DevicePermissionsPrompt::Prompt::RemoveDevice(
+    scoped_refptr<UsbDevice> device) {
+  bool removed_entry = false;
+  for (std::vector<DeviceInfo>::iterator it = devices_.begin();
+       it != devices_.end(); ++it) {
+    if (it->device == device) {
+      devices_.erase(it);
+      removed_entry = true;
+      break;
+    }
+  }
+  if (observer_ && removed_entry) {
+    observer_->OnDevicesChanged();
+  }
+}
+
+void DevicePermissionsPrompt::Prompt::OnDeviceAdded(
+    scoped_refptr<UsbDevice> device) {
+  if (!(filters_.empty() || UsbDeviceFilter::MatchesAny(device, filters_))) {
+    return;
+  }
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI, FROM_HERE,
+      base::Bind(&DevicePermissionsPrompt::Prompt::AddDevice, this,
+                 DeviceInfo(device)));
+}
+
+void DevicePermissionsPrompt::Prompt::OnDeviceRemoved(
+    scoped_refptr<UsbDevice> device) {
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI, FROM_HERE,
+      base::Bind(&DevicePermissionsPrompt::Prompt::RemoveDevice, this, device));
+}
+
 DevicePermissionsPrompt::DevicePermissionsPrompt(
     content::WebContents* web_contents)
     : web_contents_(web_contents), delegate_(nullptr) {