Move GetNewTabCSS() caching off the startup path.

chrome/browser/ui/webui/theme_source.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/ui/webui/theme_source.h"
 
 #include "base/memory/ref_counted_memory.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 44 matching lines @@
 
 void ProcessResourceOnUIThread(int resource_id,
                                float scale,
                                scoped_refptr<base::RefCountedBytes> data) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   ProcessImageOnUIThread(
       *ResourceBundle::GetSharedInstance().GetImageSkiaNamed(resource_id),
       scale, data);
 }
 
+base::RefCountedMemory* GetNewTabCSSOnUIThread(Profile* profile) {

[Evan Stade, 2016/10/03 20:16:59]

nit: style guide says NewTabCssOnUiThread

[Alexei Svitkine (slow), 2016/10/03 21:02:45]

Done - changed the other function in this file too for consistency.

+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  NTPResourceCache::WindowType type =
+      NTPResourceCache::GetWindowType(profile, nullptr);
+  return NTPResourceCacheFactory::GetForProfile(profile)->GetNewTabCSS(type);
+}
+
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // ThemeSource, public:
 
 ThemeSource::ThemeSource(Profile* profile)
-    : profile_(profile->GetOriginalProfile()) {
-  // NB: it's important that this is |profile| and not |profile_|.
-  NTPResourceCache::WindowType win_type =
-      NTPResourceCache::GetWindowType(profile, nullptr);
-  css_bytes_ =
-      NTPResourceCacheFactory::GetForProfile(profile)->GetNewTabCSS(win_type);
+    : profile_(profile),
+      original_profile_(profile->GetOriginalProfile()) {

[Evan Stade, 2016/10/03 20:16:59]

why not just inline profile_->GetOriginalProfile where it's needed?

[Alexei Svitkine (slow), 2016/10/03 21:02:45]

Done.

 }
 
 ThemeSource::~ThemeSource() {
 }
 
 std::string ThemeSource::GetSource() const {
   return chrome::kChromeUIThemeHost;
 }
 
 void ThemeSource::StartDataRequest(
     const std::string& path,
     int render_process_id,
     int render_frame_id,
     const content::URLDataSource::GotDataCallback& callback) {
   // Default scale factor if not specified.
   float scale = 1.0f;
   std::string parsed_path;
   webui::ParsePathAndScale(GetThemeUrl(path), &parsed_path, &scale);
 
   if (IsNewTabCssPath(parsed_path)) {
     DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-    callback.Run(css_bytes_.get());
+    // NB: it's important that this is |profile_| and not |original_profile_|.
+    content::BrowserThread::PostTaskAndReplyWithResult(
+        content::BrowserThread::UI, FROM_HERE,
+        base::Bind(&GetNewTabCSSOnUIThread, profile_),
+        callback);
     return;
   }
 
   int resource_id = -1;
   if (parsed_path == "current-channel-logo") {
     switch (chrome::GetChannel()) {
 #if defined(GOOGLE_CHROME_BUILD)
       case version_info::Channel::CANARY:
         resource_id = IDR_PRODUCT_LOGO_32_CANARY;
         break;
@@ skipping 59 matching lines @@
     // have to go back to the UI thread to send the data.
     return nullptr;
   }
 
   // If it's not a themeable image, we don't need to go to the UI thread.
   int resource_id = ResourcesUtil::GetThemeResourceId(parsed_path);
   return BrowserThemePack::IsPersistentImageID(resource_id) ?
       content::URLDataSource::MessageLoopForRequestPath(path) : nullptr;
 }
 
-bool ThemeSource::ShouldReplaceExistingSource() const {
-  // We currently get the css_bytes_ in the ThemeSource constructor, so we need
-  // to recreate the source itself when a theme changes.
-  return true;
-}
-
 bool ThemeSource::ShouldServiceRequest(const net::URLRequest* request) const {
   return request->url().SchemeIs(chrome::kChromeSearchScheme) ?
       InstantIOContext::ShouldServiceRequest(request) :
       URLDataSource::ShouldServiceRequest(request);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ThemeSource, private:
 
 void ThemeSource::SendThemeBitmap(
     const content::URLDataSource::GotDataCallback& callback,
     int resource_id,
     float scale) {
   ui::ScaleFactor scale_factor = ui::GetSupportedScaleFactor(scale);
   if (BrowserThemePack::IsPersistentImageID(resource_id)) {
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
     scoped_refptr<base::RefCountedMemory> image_data(
-        ThemeService::GetThemeProviderForProfile(profile_).GetRawData(
+        ThemeService::GetThemeProviderForProfile(original_profile_).GetRawData(
             resource_id, scale_factor));
     callback.Run(image_data.get());
   } else {
     DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
     const ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     callback.Run(rb.LoadDataResourceBytesForScale(resource_id, scale_factor));
   }
 }
 
 void ThemeSource::SendThemeImage(
     const content::URLDataSource::GotDataCallback& callback,
     int resource_id,
     float scale) {
   scoped_refptr<base::RefCountedBytes> data(new base::RefCountedBytes());
   if (BrowserThemePack::IsPersistentImageID(resource_id)) {
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
     const ui::ThemeProvider& tp =
-        ThemeService::GetThemeProviderForProfile(profile_);
+        ThemeService::GetThemeProviderForProfile(original_profile_);
     ProcessImageOnUIThread(*tp.GetImageSkiaNamed(resource_id), scale, data);
     callback.Run(data.get());
   } else {
     DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
     // Fetching image data in ResourceBundle should happen on the UI thread. See
     // crbug.com/449277
     content::BrowserThread::PostTaskAndReply(
         content::BrowserThread::UI, FROM_HERE,
         base::Bind(&ProcessResourceOnUIThread, resource_id, scale, data),
         base::Bind(callback, data));
   }
 }