Add support for providers called when the omnibox is focused.

chrome/browser/autocomplete/autocomplete_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/autocomplete/autocomplete_controller.h"
 
 #include <set>
 #include <string>
 
 #include "base/format_macros.h"
@@ skipping 247 matching lines @@
   // Start the new query.
   in_start_ = true;
   base::TimeTicks start_time = base::TimeTicks::Now();
   for (Providers::iterator i(providers_.begin()); i != providers_.end(); ++i) {
     // TODO(mpearson): Remove timing code once bugs 178705 / 237703 / 168933
     // are resolved.
     base::TimeTicks provider_start_time = base::TimeTicks::Now();
 
     // Call Start() on ZeroSuggestProvider with an INVALID AutocompleteInput
     // to clear out zero-suggest |matches_|.
     if (i->get() == zero_suggest_provider_)

[Maria, 2015/01/05 19:09:52]

This bit is a little strange now. Here we clear out zero suggest matches to make
sure they don't get mixed with prefix-based matches. 

This is ok for clipboard, which will run with prefix input as well as non-prefix
input and will update its matches_, but I am wondering if we get another
provider that decides to provide matches on focus, but not for prefixed input,
this will be off.

[Peter Kasting, 2015/01/05 19:31:07]

Yeah, this is weird.  I kind of think the ZeroSuggest provider, and not the
controller, ought to be making this kind of decision.  Perhaps we should simply
ensure Start() passes along enough info for it to do so.

       (*i)->Start(AutocompleteInput(), minimal_changes);
     else
       (*i)->Start(input_, minimal_changes);
 
     if (!input.want_asynchronous_matches())
       DCHECK((*i)->done());
     base::TimeTicks provider_end_time = base::TimeTicks::Now();
     std::string name = std::string("Omnibox.ProviderTime.") + (*i)->GetName();
     base::HistogramBase* counter = base::Histogram::FactoryGet(
         name, 1, 5000, 20, base::Histogram::kUmaTargetedHistogramFlag);
@@ skipping 41 matching lines @@
   stop_timer_.Stop();
   done_ = true;
   if (clear_result && !result_.empty()) {
     result_.Reset();
     // NOTE: We pass in false since we're trying to only clear the popup, not
     // touch the edit... this is all a mess and should be cleaned up :(
     NotifyChanged(false);
   }
 }
 
-void AutocompleteController::StartZeroSuggest(const AutocompleteInput& input) {
-  if (zero_suggest_provider_ == NULL)
-    return;
-
+void AutocompleteController::OnOmniboxFocused(const AutocompleteInput& input) {
   DCHECK(!in_start_);  // We should not be already running a query.
 
   // Call Start() on all prefix-based providers with an INVALID
   // AutocompleteInput to clear out cached |matches_|, which ensures that
   // they aren't used with zero suggest.
   for (Providers::iterator i(providers_.begin()); i != providers_.end(); ++i) {
-    if (i->get() == zero_suggest_provider_)
+    if ((*i)->ProvidesMatchesOnOmniboxFocus())
       (*i)->Start(input, false);
     else
       (*i)->Start(AutocompleteInput(), false);
   }
 
-  if (!zero_suggest_provider_->matches().empty())
-    UpdateResult(false, false);
+  UpdateResult(false, false);
 }
 
 void AutocompleteController::DeleteMatch(const AutocompleteMatch& match) {
   DCHECK(match.SupportsDeletion());
 
   // Delete duplicate matches attached to the main match first.
   for (ACMatches::const_iterator it(match.duplicate_matches.begin());
        it != match.duplicate_matches.end(); ++it) {
     if (it->deletable)
       it->provider->DeleteMatch(*it);
@@ skipping 321 matching lines @@
                         this, &AutocompleteController::ExpireCopiedEntries);
 }
 
 void AutocompleteController::StartStopTimer() {
   stop_timer_.Start(FROM_HERE,
                     stop_timer_duration_,
                     base::Bind(&AutocompleteController::Stop,
                                base::Unretained(this),
                                false));
 }