Revert of Cache the current WebPreferences on RenderViewHostImpl. (https://codereview.chromium.org/373323003/)

Reason for revert:
Causes DOA on 38-dev.

https://code.google.com/p/chromium/issues/detail?id=398751

Original issue's description:
> Cache the current WebPreferences on RenderViewHostImpl.
> 
> This makes lookups of a WebPreferences field fast.
> In order do this, add code to listen to all preferences updates in order to recompute the cache.
> 
> BUG=390799
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284592

TBR=jam, michaelbai, chrishtr, avi
NOTREECHECKS=true
NOTRY=true
BUG=390799

Review URL: https://codereview.chromium.org/429413003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@286876 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 16 insertions, 33 deletions

diff --git a/content/browser/android/content_settings.cc b/content/browser/android/content_settings.cc
index 2d32143..7ab181b 100644
--- a/content/browser/android/content_settings.cc
+++ b/content/browser/android/content_settings.cc
@@ -39,7 +39,7 @@ bool ContentSettings::GetJavaScriptEnabled(JNIEnv* env, jobject obj) {
   RenderViewHost* render_view_host = web_contents()->GetRenderViewHost();
   if (!render_view_host)
     return false;
-  return render_view_host->GetWebkitPreferences().javascript_enabled;
+  return render_view_host->GetDelegate()->GetWebkitPrefs().javascript_enabled;
 }
 
 void ContentSettings::WebContentsDestroyed() {
diff --git a/content/browser/browser_plugin/browser_plugin_guest.cc b/content/browser/browser_plugin/browser_plugin_guest.cc
index 1da2fdd..ef729e4 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.cc
+++ b/content/browser/browser_plugin/browser_plugin_guest.cc
@@ -223,10 +223,7 @@ void BrowserPluginGuest::Initialize(
       new BrowserPluginMsg_GuestContentWindowReady(instance_id_,
                                                    guest_routing_id));
 
-  // TODO(chrishtr): this code is wrong. The navigate_on_drag_drop field will
-  // be reset again the next time preferences are updated.
-  WebPreferences prefs =
-      GetWebContents()->GetRenderViewHost()->GetWebkitPreferences();
+  WebPreferences prefs = GetWebContents()->GetWebkitPrefs();
   prefs.navigate_on_drag_drop = false;
   GetWebContents()->GetRenderViewHost()->UpdateWebkitPreferences(prefs);
 
diff --git a/content/browser/frame_host/interstitial_page_impl.cc b/content/browser/frame_host/interstitial_page_impl.cc
index f2cac9c..1a1ed43 100644
--- a/content/browser/frame_host/interstitial_page_impl.cc
+++ b/content/browser/frame_host/interstitial_page_impl.cc
@@ -509,11 +509,11 @@ RendererPreferences InterstitialPageImpl::GetRendererPrefs(
   return renderer_preferences_;
 }
 
-WebPreferences InterstitialPageImpl::ComputeWebkitPrefs() {
+WebPreferences InterstitialPageImpl::GetWebkitPrefs() {
   if (!enabled())
     return WebPreferences();
 
-  return render_view_host_->ComputeWebkitPrefs(url_);
+  return render_view_host_->GetWebkitPrefs(url_);
 }
 
 void InterstitialPageImpl::RenderWidgetDeleted(
diff --git a/content/browser/frame_host/interstitial_page_impl.h b/content/browser/frame_host/interstitial_page_impl.h
index 1305eea..7f2d4d7 100644
--- a/content/browser/frame_host/interstitial_page_impl.h
+++ b/content/browser/frame_host/interstitial_page_impl.h
@@ -131,7 +131,7 @@ class CONTENT_EXPORT InterstitialPageImpl
                                     int error_code) OVERRIDE;
   virtual RendererPreferences GetRendererPrefs(
       BrowserContext* browser_context) const OVERRIDE;
-  virtual WebPreferences ComputeWebkitPrefs() OVERRIDE;
+  virtual WebPreferences GetWebkitPrefs() OVERRIDE;
   virtual gfx::Rect GetRootWindowResizerRect() const OVERRIDE;
   virtual void CreateNewWindow(
       int render_process_id,
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 86875b4..7218e14 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -2123,7 +2123,7 @@ void RenderProcessHostImpl::OnGpuSwitching() {
       continue;
 
     RenderViewHost* rvh = RenderViewHost::From(widget);
-    rvh->OnWebkitPreferencesChanged();
+    rvh->UpdateWebkitPreferences(rvh->GetWebkitPreferences());
   }
 }
 
diff --git a/content/browser/renderer_host/render_view_host_delegate.cc b/content/browser/renderer_host/render_view_host_delegate.cc
index 41a110e..9c0f17f 100644
--- a/content/browser/renderer_host/render_view_host_delegate.cc
+++ b/content/browser/renderer_host/render_view_host_delegate.cc
@@ -22,7 +22,7 @@ WebContents* RenderViewHostDelegate::GetAsWebContents() {
   return NULL;
 }
 
-WebPreferences RenderViewHostDelegate::ComputeWebkitPrefs() {
+WebPreferences RenderViewHostDelegate::GetWebkitPrefs() {
   return WebPreferences();
 }
 
diff --git a/content/browser/renderer_host/render_view_host_delegate.h b/content/browser/renderer_host/render_view_host_delegate.h
index 8c453a3..4a44123 100644
--- a/content/browser/renderer_host/render_view_host_delegate.h
+++ b/content/browser/renderer_host/render_view_host_delegate.h
@@ -139,9 +139,9 @@ class CONTENT_EXPORT RenderViewHostDelegate {
   virtual RendererPreferences GetRendererPrefs(
       BrowserContext* browser_context) const = 0;
 
-  // Computes a WebPreferences object that will be used by the renderer
+  // Returns a WebPreferences object that will be used by the renderer
   // associated with the owning render view host.
-  virtual WebPreferences ComputeWebkitPrefs();
+  virtual WebPreferences GetWebkitPrefs();
 
   // Notification the user has made a gesture while focus was on the
   // page. This is used to avoid uninitiated user downloads (aka carpet
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index 06b993c..0be391e 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -289,7 +289,7 @@ bool RenderViewHostImpl::CreateRenderView(
   ViewMsg_New_Params params;
   params.renderer_preferences =
       delegate_->GetRendererPrefs(GetProcess()->GetBrowserContext());
-  params.web_preferences = GetWebkitPreferences();
+  params.web_preferences = delegate_->GetWebkitPrefs();
   params.view_id = GetRoutingID();
   params.main_frame_routing_id = main_frame_routing_id_;
   params.surface_id = surface_id();
@@ -329,7 +329,7 @@ void RenderViewHostImpl::SyncRendererPrefs() {
                                         GetProcess()->GetBrowserContext())));
 }
 
-WebPreferences RenderViewHostImpl::ComputeWebkitPrefs(const GURL& url) {
+WebPreferences RenderViewHostImpl::GetWebkitPrefs(const GURL& url) {
   TRACE_EVENT0("browser", "RenderViewHostImpl::GetWebkitPrefs");
   WebPreferences prefs;
 
@@ -1418,10 +1418,7 @@ void RenderViewHostImpl::ExitFullscreen() {
 }
 
 WebPreferences RenderViewHostImpl::GetWebkitPreferences() {
-  if (!web_preferences_.get()) {
-    OnWebkitPreferencesChanged();
-  }
-  return *web_preferences_;
+  return delegate_->GetWebkitPrefs();
 }
 
 void RenderViewHostImpl::DisownOpener() {
@@ -1432,14 +1429,9 @@ void RenderViewHostImpl::DisownOpener() {
 }
 
 void RenderViewHostImpl::UpdateWebkitPreferences(const WebPreferences& prefs) {
-  web_preferences_.reset(new WebPreferences(prefs));
   Send(new ViewMsg_UpdateWebPreferences(GetRoutingID(), prefs));
 }
 
-void RenderViewHostImpl::OnWebkitPreferencesChanged() {
-  UpdateWebkitPreferences(delegate_->ComputeWebkitPrefs());
-}
-
 void RenderViewHostImpl::GetAudioOutputControllers(
     const GetAudioOutputControllersCallback& callback) const {
   AudioRendererHost* audio_host =
diff --git a/content/browser/renderer_host/render_view_host_impl.h b/content/browser/renderer_host/render_view_host_impl.h
index 250204e..e2a9764 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -204,7 +204,6 @@ class CONTENT_EXPORT RenderViewHostImpl
   virtual WebPreferences GetWebkitPreferences() OVERRIDE;
   virtual void UpdateWebkitPreferences(
       const WebPreferences& prefs) OVERRIDE;
-  virtual void OnWebkitPreferencesChanged() OVERRIDE;
   virtual void GetAudioOutputControllers(
       const GetAudioOutputControllersCallback& callback) const OVERRIDE;
   virtual void SelectWordAroundCaret() OVERRIDE;
@@ -242,7 +241,7 @@ class CONTENT_EXPORT RenderViewHostImpl
   }
 
   // Returns the content specific prefs for this RenderViewHost.
-  WebPreferences ComputeWebkitPrefs(const GURL& url);
+  WebPreferences GetWebkitPrefs(const GURL& url);
 
   // Sends the given navigation message. Use this rather than sending it
   // yourself since this does the internal bookkeeping described below. This
@@ -608,11 +607,6 @@ class CONTENT_EXPORT RenderViewHostImpl
   // True if the current focused element is editable.
   bool is_focused_element_editable_;
 
-  // This is updated every time UpdateWebkitPreferences is called. That method
-  // is in turn called when any of the settings change that the WebPreferences
-  // values depend on.
-  scoped_ptr<WebPreferences> web_preferences_;
-
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostImpl);
 };
 
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index a0bf9b3..9c40100 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -3846,7 +3846,7 @@ bool WebContentsImpl::AddMessageToConsole(int32 level,
                                         source_id);
 }
 
-WebPreferences WebContentsImpl::ComputeWebkitPrefs() {
+WebPreferences WebContentsImpl::GetWebkitPrefs() {
   // We want to base the page config off of the actual URL, rather than the
   // virtual URL.
   // TODO(nasko): Investigate how to remove the GetActiveEntry usage here,
@@ -3854,7 +3854,7 @@ WebPreferences WebContentsImpl::ComputeWebkitPrefs() {
   GURL url = controller_.GetActiveEntry()
       ? controller_.GetActiveEntry()->GetURL() : GURL::EmptyGURL();
 
-  return GetRenderManager()->current_host()->ComputeWebkitPrefs(url);
+  return GetRenderManager()->current_host()->GetWebkitPrefs(url);
 }
 
 int WebContentsImpl::CreateSwappedOutRenderView(
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index fd69e98..aee4309 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -417,7 +417,7 @@ class CONTENT_EXPORT WebContentsImpl
                                    const base::string16& source_id) OVERRIDE;
   virtual RendererPreferences GetRendererPrefs(
       BrowserContext* browser_context) const OVERRIDE;
-  virtual WebPreferences ComputeWebkitPrefs() OVERRIDE;
+  virtual WebPreferences GetWebkitPrefs() OVERRIDE;
   virtual void OnUserGesture() OVERRIDE;
   virtual void OnIgnoredUIEvent() OVERRIDE;
   virtual void RendererUnresponsive(RenderViewHost* render_view_host,