Don't capture screenshots for in-page navigations.

content/browser/frame_host/navigator_impl.cc

 // Copyright 2013 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 "content/browser/frame_host/navigator_impl.h"
 
 #include "base/command_line.h"
 #include "base/time/time.h"
 #include "content/browser/frame_host/frame_tree.h"
 #include "content/browser/frame_host/frame_tree_node.h"
@@ skipping 423 matching lines @@
 
   if (PageTransitionIsMainFrame(params.transition)) {
     if (delegate_) {
       // When overscroll navigation gesture is enabled, a screenshot of the page
       // in its current state is taken so that it can be used during the
       // nav-gesture. It is necessary to take the screenshot here, before
       // calling RenderFrameHostManager::DidNavigateMainFrame, because that can
       // change WebContents::GetRenderViewHost to return the new host, instead
       // of the one that may have just been swapped out.
       if (delegate_->CanOverscrollContent()) {
-        bool page_id_changed;
-        bool url_changed;
-        NavigationEntry* current_entry = controller_->GetLastCommittedEntry();
-        if (current_entry) {
-          page_id_changed = params.page_id > 0 &&
-              params.page_id != current_entry->GetPageID();
-          url_changed = params.url != current_entry->GetURL();
-        } else {
-          page_id_changed = params.page_id > 0;
-          url_changed = params.url != GURL::EmptyGURL();
-        }
-
-        // We only want to take the screenshot if the are navigating to a
-        // different history entry than the current one. So if neither the
-        // page id nor the url changed - don't take the screenshot.
-        if (page_id_changed || url_changed)
+        // Don't take screenshots if we are staying on the same page. We want
+        // in-page navigations to be super fast, and taking a screenshot
+        // currently blocks GPU for a longer time than we are willing to
+        // tolerate in this use case.
+        if (!params.was_within_same_page)
           controller_->TakeScreenshot();
       }
 
       // Run tasks that must execute just before the commit.
       bool is_navigation_within_page = controller_->IsURLInPageNavigation(
           params.url, params.was_within_same_page, render_frame_host);
       delegate_->DidNavigateMainFramePreCommit(is_navigation_within_page);
     }
 
     if (!use_site_per_process)
@@ skipping 172 matching lines @@
 
     // Navigations in Web UI pages count as browser-initiated navigations.
     params.is_renderer_initiated = false;
   }
 
   if (delegate_)
     delegate_->RequestOpenURL(render_frame_host, params);
 }
 
 }  // namespace content