Fail gracefully when libusb_init fails

Fail gracefully when libusb_init fails

BUG=280668
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=221508

[Bei Zhang, 2013-09-04 18:43:36]

Hi Xiyuan,

Please review.

Thanks,
Bei

[xiyuan, 2013-09-04 20:22:22]

LGTM

Thank you for fixing this. 
You might still need an extensions OWNER to stamp on the CL since I am not in
that list.

https://codereview.chromium.org/23571007/diff/1/chrome/browser/usb/usb_servic...
File chrome/browser/usb/usb_service.cc (right):

https://codereview.chromium.org/23571007/diff/1/chrome/browser/usb/usb_servic...
chrome/browser/usb/usb_service.cc:87: if (!context)
nit: should we check the return code of libusb_init instead of relying on it to
nullify |context|?

[Bei Zhang, 2013-09-04 21:04:58]

https://codereview.chromium.org/23571007/diff/1/chrome/browser/usb/usb_servic...
File chrome/browser/usb/usb_service.cc (right):

https://codereview.chromium.org/23571007/diff/1/chrome/browser/usb/usb_servic...
chrome/browser/usb/usb_service.cc:87: if (!context)
I see. There's chance that context is not even initialized.

On 2013/09/04 20:22:22, xiyuan wrote:
> nit: should we check the return code of libusb_init instead of relying on it
to
> nullify |context|?

[commit-bot: I haz the power, 2013-09-04 22:51:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ikarienator@chromium.org/23571007/5001

[commit-bot: I haz the power, 2013-09-04 22:51:22]

Failed to apply patch for chrome/browser/extensions/api/usb/usb_api.cc:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file chrome/browser/extensions/api/usb/usb_api.cc
  Hunk #1 FAILED at 59.
  Hunk #2 FAILED at 412.
  Hunk #3 FAILED at 537.
  Hunk #4 FAILED at 624.
  4 out of 4 hunks FAILED -- saving rejects to file
chrome/browser/extensions/api/usb/usb_api.cc.rej

Patch:       chrome/browser/extensions/api/usb/usb_api.cc
Index: chrome/browser/extensions/api/usb/usb_api.cc
diff --git a/chrome/browser/extensions/api/usb/usb_api.cc
b/chrome/browser/extensions/api/usb/usb_api.cc
index
e6ca32719227234f0c338b134e3f11198121cd34..f6bf5c174408d1beb05f4bb4926e4f2c7bec0f16
100644
--- a/chrome/browser/extensions/api/usb/usb_api.cc
+++ b/chrome/browser/extensions/api/usb/usb_api.cc
@@ -59,6 +59,8 @@ namespace {
 const char kDataKey[] = "data";
 const char kResultCodeKey[] = "resultCode";
 
+const char kErrorInitService[] = "Failed to initialize USB service.";
+
 const char kErrorOpen[] = "Failed to open device.";
 const char kErrorCancelled[] = "Transfer was cancelled.";
 const char kErrorDisconnect[] = "Device disconnected.";
@@ -412,6 +414,10 @@ UsbAsyncApiFunction::GetDeviceOrOrCompleteWithError(
   }
 
   UsbService* service = UsbService::GetInstance();
+  if (!service) {
+    CompleteWithError(kErrorInitService);
+    return NULL;
+  }
   scoped_refptr<UsbDevice> device;
 
   device = service->GetDeviceById(input_device.device);
@@ -537,6 +543,11 @@ void UsbFindDevicesFunction::AsyncWorkStart() {
   }
 
   UsbService *service = UsbService::GetInstance();
+  if (!service) {
+    CompleteWithError(kErrorInitService);
+    return;
+  }
+
   ScopedDeviceVector devices(new DeviceVector());
   service->GetDevices(devices.get());
 
@@ -624,6 +635,11 @@ void UsbGetDevicesFunction::AsyncWorkStart() {
   }
 
   UsbService* service = UsbService::GetInstance();
+  if (!service) {
+    CompleteWithError(kErrorInitService);
+    return;
+  }
+
   DeviceVector devices;
   service->GetDevices(&devices);

[commit-bot: I haz the power, 2013-09-05 17:14:15]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ikarienator@chromium.org/23571007/16001

[commit-bot: I haz the power, 2013-09-05 20:43:41]

Change committed as 221508