PlzNavigate: Improvements to RFHM commit logic.

content/browser/frame_host/render_frame_host_manager.cc

Index: content/browser/frame_host/render_frame_host_manager.cc
diff --git a/content/browser/frame_host/render_frame_host_manager.cc b/content/browser/frame_host/render_frame_host_manager.cc
index 29771b2ab65da73c748a60643a0634acce2ec5a2..2cca8ac3b753e38a64709a43ff524495885189c4 100644
--- a/content/browser/frame_host/render_frame_host_manager.cc
+++ b/content/browser/frame_host/render_frame_host_manager.cc
@@ -460,9 +460,21 @@ void RenderFrameHostManager::CommitPendingIfNecessary(
     if (render_frame_host == speculative_render_frame_host_.get()) {
       CommitPending();
     } else if (render_frame_host == render_frame_host_.get()) {
-      // TODO(carlosk): this code doesn't properly handle in-page navigation or
-      // interwoven navigation requests.
-      DCHECK(!speculative_render_frame_host_);
+      DCHECK(!should_reuse_web_ui_ || web_ui_);
+      // When the current RenderFrameHost is committing there's still the
+      // possibility that there is a speculative WebUI to be made active.
+      // But if there's also a speculative RenderFrameHost set it means the
+      // WebUI was not meant for the current one.
+      // TODO(carlosk): this code might not handle interwoven navigation
+      // requests properly. For example if two navigations, both to the current

[clamy, 2015/04/01 15:53:40]

nit: "if two navigations to the current RenderFrameHost are requested closely to
each other,..."

[carlosk, 2015/04/01 18:39:21]

Done.

+      // RenderFrameHost, requested closely to each other, one requiring a new
+      // WebUI and the other requiring none, it might happen that a WebUI is set
+      // when it shouldn't or the other way around.
+      if (speculative_web_ui_ && !speculative_render_frame_host_) {
+        CommitPending();
+      } else {
+        CleanUpNavigation();
+      }
     } else {
       // No one else should be sending us a DidNavigate in this state.
       DCHECK(false);
@@ -1637,9 +1649,17 @@ void RenderFrameHostManager::CommitPending() {
     }
   } else {
     // PlzNavigate
-    if (!should_reuse_web_ui_)
+    if (speculative_web_ui_) {
+      DCHECK(!should_reuse_web_ui_);
       web_ui_.reset(speculative_web_ui_.release());
+    } else if (should_reuse_web_ui_) {
+      DCHECK(web_ui_);
+      should_reuse_web_ui_ = false;
+    } else {
+      web_ui_.reset();
+    }
     DCHECK(!speculative_web_ui_);
+    DCHECK(!should_reuse_web_ui_);
   }
 
   // It's possible for the pending_render_frame_host_ to be nullptr when we