Revert "Defer location change events and processing during page load"

This reverts commit 047c361c.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Defer location change events and processing during page load
> 
> Improves speed of page load stress test from 146 seconds to 43 seconds.
> 
> Also add logging for accessibility page load speed.
> 
> Bug: 976849
> Change-Id: I51d2833366b7b54b2abb9fde40811d29ef287aef
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1675917
> Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
> Commit-Queue: Nektarios Paisios <nektar@chromium.org>
> Reviewed-by: Nektarios Paisios <nektar@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#672315}

TBR=nektar@chromium.org,aleventhal@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 976849
Change-Id: I0ef892affa0f6c9a2888307262f12bc720c55148
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1761715Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#689150}

content/renderer/accessibility/render_accessibility_impl.cc

@@ -191,7 +191,6 @@ void RenderAccessibilityImpl::DidCreateNewDocument() {
 void RenderAccessibilityImpl::DidCommitProvisionalLoad(
     bool is_same_document_navigation,
     ui::PageTransition transition) {
-  is_initial_load_processed_ = false;
   has_injected_stylesheet_ = false;
   // Remove the image annotator if the page is loading and it was added for
   // the one-shot image annotation (i.e. AXMode for image annotation is not
@@ -643,8 +642,6 @@ void RenderAccessibilityImpl::SendPendingAccessibilityEvents() {
     // ids to locations.
     for (size_t j = 0; j < update.nodes.size(); ++j) {
       ui::AXNodeData& src = update.nodes[j];
-      // TODO(accessibility) What if location hasn't been set yet?
-      // Get cached location for this node or create a new entry if none exists.
       ui::AXRelativeBounds& dst = locations_[update.nodes[j].id];
       dst = src.relative_bounds;
     }
@@ -664,13 +661,11 @@ void RenderAccessibilityImpl::SendPendingAccessibilityEvents() {
                                             ack_token_));
   reset_token_ = 0;
 
-  if (had_layout_complete_messages && is_initial_load_processed_)
+  if (had_layout_complete_messages)
     SendLocationChanges();
 
-  if (had_load_complete_messages) {
+  if (had_load_complete_messages)
     has_injected_stylesheet_ = false;
-    is_initial_load_processed_ = true;
-  }
 
   if (image_annotation_debugging_)
     AddImageAnnotationDebuggingAttributes(bundle.updates);

content/renderer/accessibility/render_accessibility_impl.h

@@ -242,9 +242,6 @@ class CONTENT_EXPORT RenderAccessibilityImpl
   // for debugging.
   bool image_annotation_debugging_ = false;
 
-  // Has all data related to the initial page load been processed.
-  bool is_initial_load_processed_ = false;
-
   // So we can queue up tasks to be executed later.
   base::WeakPtrFactory<RenderAccessibilityImpl> weak_factory_{this};