Mac: Fix renderer idle cpu usage regression.

Since polling is required only for the preferred height and mac only needs preferred width, add a flag that specifies if the client is interested in width and/or height.

This is a band-aid, the Real Fix is tracked in 44850.

BUG=44494
TEST=Open chrome's task manager. Idle renderer processes should take close to 0 %cpu instead of ~1.5 before.

Review URL: http://codereview.chromium.org/2145002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@48056 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 42 insertions, 18 deletions

diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
index 1ae5aca..1a98b0d 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -712,7 +712,8 @@ void ExtensionHost::RenderViewCreated(RenderViewHost* render_view_host) {
       extension_host_type_ == ViewType::EXTENSION_MOLE ||
       extension_host_type_ == ViewType::EXTENSION_POPUP ||
       extension_host_type_ == ViewType::EXTENSION_INFOBAR) {
-    render_view_host->EnablePreferredSizeChangedMode();
+    render_view_host->EnablePreferredSizeChangedMode(
+        kPreferredSizeWidth | kPreferredSizeHeightThisIsSlow);
   }
 }
 
diff --git a/chrome/browser/notifications/balloon_host.cc b/chrome/browser/notifications/balloon_host.cc
index 3dbefdc..56c6b93 100644
--- a/chrome/browser/notifications/balloon_host.cc
+++ b/chrome/browser/notifications/balloon_host.cc
@@ -15,6 +15,7 @@
 #include "chrome/common/bindings_policy.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/notification_type.h"
+#include "chrome/common/render_messages.h"
 #include "chrome/common/renderer_preferences.h"
 #include "chrome/common/url_constants.h"
 
@@ -57,7 +58,8 @@ void BalloonHost::Close(RenderViewHost* render_view_host) {
 }
 
 void BalloonHost::RenderViewCreated(RenderViewHost* render_view_host) {
-  render_view_host->EnablePreferredSizeChangedMode();
+  render_view_host->EnablePreferredSizeChangedMode(
+      kPreferredSizeWidth | kPreferredSizeHeightThisIsSlow);
 }
 
 void BalloonHost::RenderViewReady(RenderViewHost* render_view_host) {
diff --git a/chrome/browser/renderer_host/render_view_host.cc b/chrome/browser/renderer_host/render_view_host.cc
index c807f73..7d5a58a 100644
--- a/chrome/browser/renderer_host/render_view_host.cc
+++ b/chrome/browser/renderer_host/render_view_host.cc
@@ -1816,8 +1816,8 @@ void RenderViewHost::SendContentSettings(const GURL& url,
   Send(new ViewMsg_SetContentSettingsForCurrentURL(url, settings));
 }
 
-void RenderViewHost::EnablePreferredSizeChangedMode() {
-  Send(new ViewMsg_EnablePreferredSizeChangedMode(routing_id()));
+void RenderViewHost::EnablePreferredSizeChangedMode(int flags) {
+  Send(new ViewMsg_EnablePreferredSizeChangedMode(routing_id(), flags));
 }
 
 void RenderViewHost::OnExtensionPostMessage(
diff --git a/chrome/browser/renderer_host/render_view_host.h b/chrome/browser/renderer_host/render_view_host.h
index 97467f4..cd97788 100644
--- a/chrome/browser/renderer_host/render_view_host.h
+++ b/chrome/browser/renderer_host/render_view_host.h
@@ -462,8 +462,10 @@ class RenderViewHost : public RenderWidgetHost {
                            const ContentSettings& settings);
 
   // Tells the renderer to notify us when the page contents preferred size
-  // changed.
-  void EnablePreferredSizeChangedMode();
+  // changed. |flags| is a combination of
+  // |ViewHostMsg_EnablePreferredSizeChangedMode_Flags| values, which is defined
+  // in render_messages.h.
+  void EnablePreferredSizeChangedMode(int flags);
 
  protected:
   // RenderWidgetHost protected overrides.
diff --git a/chrome/browser/tab_contents/tab_contents.cc b/chrome/browser/tab_contents/tab_contents.cc
index 3e38fe0..f3160cc 100644
--- a/chrome/browser/tab_contents/tab_contents.cc
+++ b/chrome/browser/tab_contents/tab_contents.cc
@@ -789,8 +789,10 @@ bool TabContents::NavigateToPendingEntry(
   if (!dest_render_view_host)
     return false;  // Unable to create the desired render view host.
 
-  if (delegate_ && delegate_->ShouldEnablePreferredSizeNotifications())
-    dest_render_view_host->EnablePreferredSizeChangedMode();
+  if (delegate_ && delegate_->ShouldEnablePreferredSizeNotifications()) {
+    dest_render_view_host->EnablePreferredSizeChangedMode(
+        kPreferredSizeWidth | kPreferredSizeHeightThisIsSlow);
+  }
 
   // For security, we should never send non-DOM-UI URLs (other than about:blank)
   // to a DOM UI renderer.  Double check that here.
diff --git a/chrome/browser/tab_contents/tab_contents_view_mac.mm b/chrome/browser/tab_contents/tab_contents_view_mac.mm
index 92cbe2d..9de79b9 100644
--- a/chrome/browser/tab_contents/tab_contents_view_mac.mm
+++ b/chrome/browser/tab_contents/tab_contents_view_mac.mm
@@ -154,10 +154,10 @@ void TabContentsViewMac::StartDragging(
 }
 
 void TabContentsViewMac::RenderViewCreated(RenderViewHost* host) {
-  // We want updates whenever the intrinsic width of the webpage
-  // changes. Put the RenderView into that mode.
-  int routing_id = host->routing_id();
-  host->Send(new ViewMsg_EnablePreferredSizeChangedMode(routing_id));
+  // We want updates whenever the intrinsic width of the webpage changes.
+  // Put the RenderView into that mode. The preferred width is used for example
+  // when the "zoom" button in the browser window is clicked.
+  host->EnablePreferredSizeChangedMode(kPreferredSizeWidth);
 }
 
 void TabContentsViewMac::SetPageTitle(const std::wstring& title) {
diff --git a/chrome/common/render_messages.h b/chrome/common/render_messages.h
index 065fde0..ce94e22 100644
--- a/chrome/common/render_messages.h
+++ b/chrome/common/render_messages.h
@@ -657,6 +657,15 @@ struct ViewMsg_ExtensionExtentsUpdated_Params {
   std::vector< std::pair<std::string, ExtensionExtent> > extension_apps;
 };
 
+// Values that may be OR'd together to form the 'flags' parameter of the
+// ViewMsg_EnablePreferredSizeChangedMode message.
+enum ViewHostMsg_EnablePreferredSizeChangedMode_Flags {
+  kPreferredSizeNothing,
+  kPreferredSizeWidth = 1 << 0,
+  // Requesting the height currently requires a polling loop in render_view.cc.
+  kPreferredSizeHeightThisIsSlow = 1 << 1,
+};
+
 namespace IPC {
 
 template <>
diff --git a/chrome/common/render_messages_internal.h b/chrome/common/render_messages_internal.h
index 2f71dc6..828c0e9 100644
--- a/chrome/common/render_messages_internal.h
+++ b/chrome/common/render_messages_internal.h
@@ -763,7 +763,7 @@ IPC_BEGIN_MESSAGES(View)
   IPC_MESSAGE_ROUTED0(ViewMsg_Move_ACK)
 
   // Used to instruct the RenderView to send back updates to the preferred size.
-  IPC_MESSAGE_ROUTED0(ViewMsg_EnablePreferredSizeChangedMode)
+  IPC_MESSAGE_ROUTED1(ViewMsg_EnablePreferredSizeChangedMode, int /*flags*/)
 
   // Used to tell the renderer not to add scrollbars with height and
   // width below a threshold.
diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index e1a0dc3..832914a 100644
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -3875,13 +3875,21 @@ void RenderView::OnEnableViewSourceMode() {
   main_frame->enableViewSourceMode(true);
 }
 
-void RenderView::OnEnablePreferredSizeChangedMode() {
+void RenderView::OnEnablePreferredSizeChangedMode(int flags) {
+  DCHECK(flags != kPreferredSizeNothing);
   if (send_preferred_size_changes_)
     return;
-
   send_preferred_size_changes_ = true;
-  preferred_size_change_timer_.Start(TimeDelta::FromMilliseconds(10), this,
-                                     &RenderView::CheckPreferredSize);
+
+  // WebKit doesn't send a notification of the effective height of the page
+  // changes, so poll for it.
+  // TODO: Add a notification for this to WebKit, remove polling. After that's
+  // done, rename kPreferredSizeHeightThisIsSlow to kPreferredSizeHeight.
+  // http://crbug.com/44850
+  if (flags & kPreferredSizeHeightThisIsSlow) {
+    preferred_size_change_timer_.Start(TimeDelta::FromMilliseconds(10), this,
+                                       &RenderView::CheckPreferredSize);
+  }
 }
 
 void RenderView::OnDisableScrollbarsForSmallWindows(
diff --git a/chrome/renderer/render_view.h b/chrome/renderer/render_view.h
index 972e2a7..283f203 100644
--- a/chrome/renderer/render_view.h
+++ b/chrome/renderer/render_view.h
@@ -722,7 +722,7 @@ class RenderView : public RenderWidget,
   void OnInstallMissingPlugin();
   void OnFileChooserResponse(const std::vector<FilePath>& paths);
   void OnEnableViewSourceMode();
-  void OnEnablePreferredSizeChangedMode();
+  void OnEnablePreferredSizeChangedMode(int flags);
   void OnDisableScrollbarsForSmallWindows(
       const gfx::Size& disable_scrollbars_size_limit);
   void OnSetRendererPrefs(const RendererPreferences& renderer_prefs);