Add logs for WebAPK server failures

chrome/browser/android/webapk/webapk_installer.cc

Index: chrome/browser/android/webapk/webapk_installer.cc
diff --git a/chrome/browser/android/webapk/webapk_installer.cc b/chrome/browser/android/webapk/webapk_installer.cc
index 685f190a2b2cb9b72d83385192539017b5eeae31..567e3cbbd5153afb2458d0940203fc756a577ee3 100644
--- a/chrome/browser/android/webapk/webapk_installer.cc
+++ b/chrome/browser/android/webapk/webapk_installer.cc
@@ -400,23 +400,28 @@ void WebApkInstaller::UpdateAsync(
 void WebApkInstaller::OnURLFetchComplete(const net::URLFetcher* source) {
   timer_.Stop();
 
-  if (!source->GetStatus().is_success() ||
-      source->GetResponseCode() != net::HTTP_OK) {
+  int response_code = source->GetResponseCode();
+  std::string response_string;
+  source->GetResponseAsString(&response_string);
+
+  if (!source->GetStatus().is_success() || response_code != net::HTTP_OK) {
+    LOG(WARNING) << base::StringPrintf(
+        "WebAPK server returned response code %d %s.", response_code,
+        response_string.c_str());

[pkotwicz, 2017/02/09 21:23:56]

The response string won't look too pretty right now because it is a proto even
for errors

[Xi Han, 2017/02/09 22:02:14]

I don't think we should put the entire response_string in the log, only
|response_code| should be enough.

[pkotwicz, 2017/02/09 22:54:22]

Done.

     OnFailure();
     return;
   }
 
-  std::string response_string;
-  source->GetResponseAsString(&response_string);
-
   std::unique_ptr<webapk::WebApkResponse> response(new webapk::WebApkResponse);
   if (!response->ParseFromString(response_string)) {
+    LOG(WARNING) << "WebAPK server did not return proto.";
     OnFailure();
     return;
   }
 
   GURL signed_download_url(response->signed_download_url());
   if (!signed_download_url.is_valid() || response->package_name().empty()) {
+    LOG(WARNING) << "WebAPK server returned incomplete proto.";
     OnFailure();
     return;
   }