Gets rid of the LocationArbitrator interface, in preference for LocationProvider.

device/geolocation/location_arbitrator_impl.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 "device/geolocation/location_arbitrator_impl.h"
 
 #include <map>
+#include <memory>
+#include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "build/build_config.h"
 #include "device/geolocation/access_token_store.h"
 #include "device/geolocation/geolocation_delegate.h"
 #include "device/geolocation/network_location_provider.h"
 #include "url/gurl.h"
 
@@ skipping 26 matching lines @@
 GURL LocationArbitratorImpl::DefaultNetworkProviderURL() {
   return GURL(kDefaultNetworkProviderUrl);
 }
 
 void LocationArbitratorImpl::OnPermissionGranted() {
   is_permission_granted_ = true;
   for (const auto& provider : providers_)
     provider->OnPermissionGranted();
 }
 
-void LocationArbitratorImpl::StartProviders(bool enable_high_accuracy) {
+bool LocationArbitratorImpl::StartProvider(bool enable_high_accuracy) {
   // Stash options as OnAccessTokenStoresLoaded has not yet been called.
   is_running_ = true;
   enable_high_accuracy_ = enable_high_accuracy;
 
   if (providers_.empty()) {
     RegisterSystemProvider();
 
     const scoped_refptr<AccessTokenStore> access_token_store =
         GetAccessTokenStore();
     if (access_token_store && delegate_->UseNetworkLocationProviders()) {
       DCHECK(DefaultNetworkProviderURL().is_valid());
       token_store_callback_.Reset(
           base::Bind(&LocationArbitratorImpl::OnAccessTokenStoresLoaded,
                      base::Unretained(this)));
       access_token_store->LoadAccessTokens(token_store_callback_.callback());
-      return;
+      return true;
     }
   }
   DoStartProviders();

[Wez, 2016/08/09 01:17:04]

Looks like it might be worthwhile to have DoStartProviders return a bool
indicating whether providers_ is empty, and to return that here.

(Reason being that if there is no system provider and the caller asks for no
network providers then providers_ is empty, so we should probably fail :)

[CJ, 2016/08/11 22:06:43]

Done.

+  return true;
 }
 
 void LocationArbitratorImpl::DoStartProviders() {
   if (providers_.empty()) {
     // If no providers are available, we report an error to avoid
     // callers waiting indefinitely for a reply.
     Geoposition position;
     position.error_code = Geoposition::ERROR_CODE_PERMISSION_DENIED;
     arbitrator_update_callback_.Run(position);
     return;
   }
   for (const auto& provider : providers_)
     provider->StartProvider(enable_high_accuracy_);
 }
 
-void LocationArbitratorImpl::StopProviders() {
+void LocationArbitratorImpl::StopProvider() {
   // Reset the reference location state (provider+position)
   // so that future starts use fresh locations from
   // the newly constructed providers.
   position_provider_ = nullptr;
   position_ = Geoposition();
 
   providers_.clear();
   is_running_ = false;
 }
 
@@ skipping 33 matching lines @@
   DCHECK(new_position.Validate() ||
          new_position.error_code != Geoposition::ERROR_CODE_NONE);
   if (!IsNewPositionBetter(position_, new_position,
                            provider == position_provider_))
     return;
   position_provider_ = provider;
   position_ = new_position;
   arbitrator_update_callback_.Run(position_);
 }
 
+void LocationArbitratorImpl::RequestRefresh() {
+  if (is_permission_granted_) {
+    for (const auto& provider : providers_)
+      provider->RequestRefresh();

[Wez, 2016/08/09 01:17:04]

nit: Interesting that there are no other RequestRefresh() mentions in
LocationArbitratorImpl - are we sure that anything actually needs it? Perhaps we
could just remove it from the LocationProvider API..?

[CJ, 2016/08/11 22:06:43]

Done.

+  }
+}
+
+void LocationArbitratorImpl::GetPosition(Geoposition* position) {
+  DCHECK(position);

[Wez, 2016/08/09 01:17:04]

nit: No need to DCHECK - you're about to assign to |position|, things will
explode cleanly enough then if it's null.

[CJ, 2016/08/11 22:06:43]

Done.

+  position = &position_;

[Wez, 2016/08/09 01:17:04]

This isn't doing what you intend.

You're setting the function-local variable |position| to point to |position_| -
when GetPosition() returns there will be no observable side-effect.

What you _want_ to do is copy/assign the value of |position_| into the memory
that |position| points to, I suspect. :P

[CJ, 2016/08/11 22:06:43]

Done.

+}
+
+void LocationArbitratorImpl::SetUpdateCallback(
+    const LocationProviderUpdateCallback& callback) {
+  provider_update_callback_ = callback;
+}
+
 scoped_refptr<AccessTokenStore> LocationArbitratorImpl::NewAccessTokenStore() {
   return delegate_->CreateAccessTokenStore();
 }
 
 scoped_refptr<AccessTokenStore> LocationArbitratorImpl::GetAccessTokenStore() {
   if (!access_token_store_)
     access_token_store_ = NewAccessTokenStore();
   return access_token_store_;
 }
 
@@ skipping 50 matching lines @@
     }
   }
   return false;
 }
 
 bool LocationArbitratorImpl::HasPermissionBeenGranted() const {
   return is_permission_granted_;
 }
 
 }  // namespace device