Thumbnails: Add some perf UMA

chrome/browser/thumbnails/thumbnail_tab_helper.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 "chrome/browser/thumbnails/thumbnail_tab_helper.h"
 
 #include "base/feature_list.h"
-#include "build/build_config.h"
+#include "base/metrics/histogram_macros.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/thumbnails/thumbnail_service.h"
 #include "chrome/browser/thumbnails/thumbnail_service_factory.h"
 #include "chrome/browser/thumbnails/thumbnailing_algorithm.h"
 #include "chrome/common/chrome_features.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host.h"
 #include "content/public/browser/render_widget_host_view.h"
-#include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/scrollbar_size.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(ThumbnailTabHelper);
 
 class SkBitmap;
 
 // Overview
 // --------
 // This class provides a service for updating thumbnails to be used in
 // "Most visited" section of the new tab page. The service can be started
 // by UpdateThumbnailIfNecessary(). The current algorithm of the service is as
 // simple as follows:
 //
 //    When a renderer is about to be hidden (this usually occurs when the
 //    current tab is closed or another tab is clicked), update the
 //    thumbnail for the tab rendered by the renderer, if needed. The
 //    heuristics to judge whether or not to update the thumbnail is
 //    implemented in ShouldUpdateThumbnail().
 //    If features::kCaptureThumbnailOnLoadFinished is enabled, then a thumbnail
 //    may also be captured when a page load finishes (subject to the same
 //    heuristics).
 
 using content::RenderViewHost;
 using content::RenderWidgetHost;
 using content::WebContents;
 
 using thumbnails::ThumbnailingContext;
 using thumbnails::ThumbnailingAlgorithm;
 
-ThumbnailTabHelper::ThumbnailTabHelper(content::WebContents* contents)

[jochen (gone - plz use gerrit), 2017/05/16 11:15:17]

using content::Something should be the exception, so if you touch that, you
should rather change towards the other direction

[Marc Treib, 2017/05/16 11:48:37]

Done. (For all three "using content::"s)

+ThumbnailTabHelper::ThumbnailTabHelper(WebContents* contents)
     : content::WebContentsObserver(contents),
       capture_on_load_finished_(base::FeatureList::IsEnabled(
           features::kCaptureThumbnailOnLoadFinished)),
       load_interrupted_(false),
       weak_factory_(this) {
   // Even though we deal in RenderWidgetHosts, we only care about its
   // subclass, RenderViewHost when it is in a tab. We don't make thumbnails
   // for RenderViewHosts that aren't in tabs, or RenderWidgetHosts that
   // aren't views like select popups.
   registrar_.Add(this,
                  content::NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED,
                  content::Source<WebContents>(contents));
 }
 
-ThumbnailTabHelper::~ThumbnailTabHelper() {
-}
+ThumbnailTabHelper::~ThumbnailTabHelper() = default;
 
 void ThumbnailTabHelper::Observe(int type,
                                  const content::NotificationSource& source,
                                  const content::NotificationDetails& details) {
   switch (type) {
     case content::NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED:
       RenderViewHostCreated(content::Details<RenderViewHost>(details).ptr());
       break;
 
     case content::NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED:
@@ skipping 36 matching lines @@
 void ThumbnailTabHelper::UpdateThumbnailIfNecessary() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   // Ignore thumbnail update requests if one is already in progress.
   if (thumbnailing_context_) {
     return;
   }
 
   // Destroying a WebContents may trigger it to be hidden, prompting a snapshot
   // which would be unwise to attempt <http://crbug.com/130097>. If the
   // WebContents is in the middle of destruction, do not risk it.
-  if (!web_contents() || web_contents()->IsBeingDestroyed())
+  if (!web_contents() || web_contents()->IsBeingDestroyed()) {

[jochen (gone - plz use gerrit), 2017/05/16 11:15:17]

why this change?

if (single line)
  single line;

is already allowed

[Marc Treib, 2017/05/16 11:48:37]

For local consistency, since there are a few other single-line bodies in this
file that do have braces. If you prefer, I can change all of them to not have
braces instead (or just undo these changes - I don't care *that* much).

     return;
+  }
   // Skip if a pending entry exists. WidgetHidden can be called while navigating
   // pages and this is not a time when thumbnails should be generated.
-  if (web_contents()->GetController().GetPendingEntry())
+  if (web_contents()->GetController().GetPendingEntry()) {
     return;
+  }
   const GURL& url = web_contents()->GetURL();
   Profile* profile =
       Profile::FromBrowserContext(web_contents()->GetBrowserContext());
 
   scoped_refptr<thumbnails::ThumbnailService> thumbnail_service =
       ThumbnailServiceFactory::GetForProfile(profile);
 
   // Skip if we don't need to update the thumbnail.
   if (thumbnail_service.get() == NULL ||
       !thumbnail_service->ShouldAcquirePageThumbnail(url)) {
@@ skipping 34 matching lines @@
                                                   load_interrupted_);
 
   ui::ScaleFactor scale_factor =
       ui::GetSupportedScaleFactor(
           ui::GetScaleFactorForNativeView(view->GetNativeView()));
   thumbnailing_context_->clip_result = algorithm->GetCanvasCopyInfo(
       copy_rect.size(),
       scale_factor,
       &copy_rect,
       &thumbnailing_context_->requested_copy_size);
+  copy_from_surface_start_time_ = base::TimeTicks::Now();
   view->CopyFromSurface(copy_rect, thumbnailing_context_->requested_copy_size,
                         base::Bind(&ThumbnailTabHelper::ProcessCapturedBitmap,
                                    weak_factory_.GetWeakPtr(), algorithm),
                         kN32_SkColorType);
 }
 
 void ThumbnailTabHelper::ProcessCapturedBitmap(
     scoped_refptr<ThumbnailingAlgorithm> algorithm,
     const SkBitmap& bitmap,
     content::ReadbackResponse response) {
+  base::TimeDelta copy_from_surface_time =
+      base::TimeTicks::Now() - copy_from_surface_start_time_;
+  UMA_HISTOGRAM_TIMES("Thumbnails.CopyFromSurfaceTime", copy_from_surface_time);
+
   if (response == content::READBACK_SUCCESS) {
     // On success, we must be on the UI thread.
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    process_bitmap_start_time_ = base::TimeTicks::Now();
     algorithm->ProcessBitmap(thumbnailing_context_,
                              base::Bind(&ThumbnailTabHelper::UpdateThumbnail,
                                         weak_factory_.GetWeakPtr()),
                              bitmap);
   } else {
     // On failure because of shutdown we are not on the UI thread, so ensure
     // that cleanup happens on that thread.
     content::BrowserThread::PostTask(
         content::BrowserThread::UI,
         FROM_HERE,
         base::Bind(&ThumbnailTabHelper::CleanUpFromThumbnailGeneration,
                    weak_factory_.GetWeakPtr()));
   }
 }
 
-void ThumbnailTabHelper::CleanUpFromThumbnailGeneration() {

[Marc Treib, 2017/05/15 10:16:48]

Moved to match the order in the header.

-  // Make a note that thumbnail generation is complete.
-  thumbnailing_context_ = nullptr;
-}
-
 void ThumbnailTabHelper::UpdateThumbnail(const ThumbnailingContext& context,
                                          const SkBitmap& thumbnail) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  base::TimeDelta process_bitmap_time =
+      base::TimeTicks::Now() - process_bitmap_start_time_;
+  UMA_HISTOGRAM_TIMES("Thumbnails.ProcessBitmapTime", process_bitmap_time);
+
   // Feed the constructed thumbnail to the thumbnail service.
   gfx::Image image = gfx::Image::CreateFrom1xBitmap(thumbnail);
   context.service->SetPageThumbnail(context, image);
   DVLOG(1) << "Thumbnail taken for " << context.url << ": "
       << context.score.ToString();
 
   CleanUpFromThumbnailGeneration();
 }
 
+void ThumbnailTabHelper::CleanUpFromThumbnailGeneration() {
+  // Make a note that thumbnail generation is complete.
+  thumbnailing_context_ = nullptr;
+}
+
 void ThumbnailTabHelper::RenderViewHostCreated(RenderViewHost* renderer) {
   // NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED is really a new
   // RenderView, not RenderViewHost, and there is no good way to get
   // notifications of RenderViewHosts. So just be tolerant of re-registrations.
   bool registered = registrar_.IsRegistered(
       this, content::NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED,
       content::Source<RenderWidgetHost>(renderer->GetWidget()));
   if (!registered) {
     registrar_.Add(this, content::NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED,
                    content::Source<RenderWidgetHost>(renderer->GetWidget()));
   }
 }
 
 void ThumbnailTabHelper::WidgetHidden(RenderWidgetHost* widget) {
   UpdateThumbnailIfNecessary();
 }