Handle interface to prerenders.

chrome/browser/predictors/autocomplete_action_predictor.cc

Index: chrome/browser/predictors/autocomplete_action_predictor.cc
diff --git a/chrome/browser/predictors/autocomplete_action_predictor.cc b/chrome/browser/predictors/autocomplete_action_predictor.cc
index 2ac67fa6c65b71987b8115c7a96983df3876f2fd..28bfe6b855c1216adf48fd217d7d51d1ec3367ff 100644
--- a/chrome/browser/predictors/autocomplete_action_predictor.cc
+++ b/chrome/browser/predictors/autocomplete_action_predictor.cc
@@ -26,6 +26,7 @@
 #include "chrome/browser/predictors/predictor_database.h"
 #include "chrome/browser/predictors/predictor_database_factory.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
+#include "chrome/browser/prerender/prerender_handle.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/profiles/profile.h"
@@ -153,6 +154,19 @@ void AutocompleteActionPredictor::ClearTransitionalMatches() {
   transitional_matches_.clear();
 }
 
+void AutocompleteActionPredictor::StartPrerendering(
+    const GURL& url,
+    content::SessionStorageNamespace* session_storage_namespace,
+    const gfx::Size& size) {
+  prerender_handle_.reset();

[dominich, 2012/07/12 16:16:48]

I'm not a fan of the double reset. Would something like:

PrerenderHandle* handle = NULL;
if (... GetForProfile(...)) {
  handle = prerender_manager->AddPrerenderFromOmnibox(...);
}
prerender_handle_.reset(handle);

satisfy mmenke and gavinp?

[mmenke, 2012/07/12 16:26:51]

This affects the final status.  Resetting the old prerender handle results in a
cancellation, while swapping will result in an eviction.

[gavinp, 2012/07/13 12:02:22]

Added a comment explaining why the reset first is important.

On 2012/07/12 16:26:51, Matt Menke wrote:

+  if (prerender::PrerenderManager* prerender_manager =
+          prerender::PrerenderManagerFactory::GetForProfile(profile_)) {
+    prerender_handle_.reset(
+        prerender_manager->AddPrerenderFromOmnibox(
+            url, session_storage_namespace, size));
+  }
+}
+
 // Given a match, return a recommended action.
 AutocompleteActionPredictor::Action
     AutocompleteActionPredictor::RecommendAction(