Make Network Predictor skip empty urls

chrome/browser/net/predictor.cc

Index: chrome/browser/net/predictor.cc
diff --git a/chrome/browser/net/predictor.cc b/chrome/browser/net/predictor.cc
index 2bb76985c1f3fe406b96bded8cf87e81b314ab89..b3e96ac64e0e8cccc617213a373f50af1558391d 100644
--- a/chrome/browser/net/predictor.cc
+++ b/chrome/browser/net/predictor.cc
@@ -171,12 +171,13 @@ void Predictor::AnticipateOmniboxUrl(const GURL& url, bool preconnectable) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (!PredictorEnabled())
     return;
-  if (!url.is_valid() || !url.has_host())
+  GURL canonicalized_url = CanonicalizeUrl(url);

[Charlie Harrison, 2017/05/15 00:01:07]

Here and below can you make sure we canoncalize the URL only if
preconnect/preresolve is enabled? The URL canonicalization we do is kinda
expensive.

[xunjieli, 2017/05/15 16:41:44]

Done.

+  if (!canonicalized_url.is_valid() || !canonicalized_url.has_host())
     return;
   if (!CanPreresolveAndPreconnect())
     return;
 
-  std::string host = url.HostNoBrackets();
+  std::string host = canonicalized_url.HostNoBrackets();
   bool is_new_host_request = (host != last_omnibox_host_);
   last_omnibox_host_ = host;
 
@@ -212,7 +213,7 @@ void Predictor::AnticipateOmniboxUrl(const GURL& url, bool preconnectable) {
         return;  // We've done a preconnect recently.
       last_omnibox_preconnect_ = now;
       const int kConnectionsNeeded = 1;
-      PreconnectUrl(CanonicalizeUrl(url), GURL(), motivation,
+      PreconnectUrl(canonicalized_url, GURL(), motivation,
                     kAllowCredentialsOnPreconnectByDefault, kConnectionsNeeded);
       return;  // Skip pre-resolution, since we'll open a connection.
     }
@@ -235,24 +236,26 @@ void Predictor::AnticipateOmniboxUrl(const GURL& url, bool preconnectable) {
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::BindOnce(&Predictor::Resolve, base::Unretained(this),
-                     CanonicalizeUrl(url), motivation));
+                     canonicalized_url, motivation));
 }
 
 void Predictor::PreconnectUrlAndSubresources(const GURL& url,
     const GURL& first_party_for_cookies) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
          BrowserThread::CurrentlyOn(BrowserThread::IO));
-  if (!PredictorEnabled() || !url.is_valid() ||
-      !url.has_host())
+  GURL canonicalized_url = CanonicalizeUrl(url);
+  if (!PredictorEnabled() || !canonicalized_url.is_valid() ||
+      !canonicalized_url.has_host())
     return;
   if (!CanPreresolveAndPreconnect())
     return;
 
   UrlInfo::ResolutionMotivation motivation(UrlInfo::EARLY_LOAD_MOTIVATED);
   const int kConnectionsNeeded = 1;
-  PreconnectUrl(CanonicalizeUrl(url), first_party_for_cookies, motivation,
+  PreconnectUrl(canonicalized_url, first_party_for_cookies, motivation,
                 kConnectionsNeeded, kAllowCredentialsOnPreconnectByDefault);
-  PredictFrameSubresources(url.GetWithEmptyPath(), first_party_for_cookies);
+  PredictFrameSubresources(canonicalized_url.GetWithEmptyPath(),
+                           first_party_for_cookies);
 }
 
 std::vector<GURL> Predictor::GetPredictedUrlListAtStartup(
@@ -725,6 +728,7 @@ void Predictor::PreconnectUrl(const GURL& url,
                               int count) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
          BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK(url.is_valid());
 
   if (BrowserThread::CurrentlyOn(BrowserThread::IO)) {
     PreconnectUrlOnIOThread(url, first_party_for_cookies, motivation,