toggle FPS counter in compositor

cc/layer_tree_host.cc

Index: cc/layer_tree_host.cc
diff --git a/cc/layer_tree_host.cc b/cc/layer_tree_host.cc
index c6d3003279fe669bbd01f13c33a3db5e99ef2f29..bcc42bb71a4969b8ea1729804ae0dfb28f36c806 100644
--- a/cc/layer_tree_host.cc
+++ b/cc/layer_tree_host.cc
@@ -38,7 +38,6 @@ bool CCLayerTreeHost::s_needsFilterContext = false;
 
 CCLayerTreeSettings::CCLayerTreeSettings()
     : acceleratePainting(false)
-    , showFPSCounter(false)
     , showPlatformLayerTree(false)
     , showPaintRects(false)
     , showPropertyChangedRects(false)
@@ -277,25 +276,35 @@ void CCLayerTreeHost::finishCommitOnImplThread(CCLayerTreeHostImpl* hostImpl)
     m_commitNumber++;
 }
 
+void CCLayerTreeHost::setShowFPSCounter(bool show)
+{
+    createHUDLayerIfNeeded();

[danakj, 2012/10/23 15:19:53]

Can we DCHECK some stuff here?
DCHECK(m_hudLayer);
DCHECK(m_hudLayer->hasFontAtlas());

This means that we have to setFontAtlast *before* setShowFPSCounter on the
webkit side, but I'd like some DCHECKs here for future code-movings.

+    m_hudLayer->setShowFPSCounter(show);
+    setNeedsCommit();
+}
+
 void CCLayerTreeHost::setFontAtlas(scoped_ptr<CCFontAtlas> fontAtlas)
 {
-    m_fontAtlas = fontAtlas.Pass();
+    createHUDLayerIfNeeded();
+    m_hudLayer->setFontAtlas(fontAtlas.Pass());
     setNeedsCommit();
 }
 
+void CCLayerTreeHost::createHUDLayerIfNeeded()
+{
+    if (!m_hudLayer)
+        m_hudLayer = HeadsUpDisplayLayerChromium::create();
+}
+
 void CCLayerTreeHost::willCommit()
 {
     m_client->willCommit();
-    if (m_rootLayer && m_settings.showDebugInfo()) {
-        if (!m_hudLayer)
-            m_hudLayer = HeadsUpDisplayLayerChromium::create();
 
-        if (m_fontAtlas.get())
-            m_hudLayer->setFontAtlas(m_fontAtlas.Pass());
+    if (m_settings.showDebugRects())

[danakj, 2012/10/23 15:19:53]

This is missing m_settings.showPlatformLayerTree. Use showDebugInfo() instead?

+        createHUDLayerIfNeeded();
 
-        if (!m_hudLayer->parent())
-            m_rootLayer->addChild(m_hudLayer);
-    }
+    if (m_rootLayer && m_hudLayer && !m_hudLayer->parent())
+        m_rootLayer->addChild(m_hudLayer);
 }
 
 void CCLayerTreeHost::commitComplete()