Use RecalcStyleDeferred for inspector style changes.

Source/core/inspector/InspectorPageAgent.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1139 matching lines @@
 
     m_deviceMetricsOverridden = enabled;
     m_emulateViewportEnabled = emulateViewport;
     if (enabled)
         m_client->setDeviceMetricsOverride(width, height, static_cast<float>(deviceScaleFactor), emulateViewport, fitWindow);
     else
         m_client->clearDeviceMetricsOverride();
 
     Document* document = mainFrame()->document();
     if (document) {
-        document->styleResolverChanged(RecalcStyleImmediately);
+        document->styleResolverChanged(RecalcStyleDeferred);
         document->mediaQueryAffectingValueChanged();
     }
     InspectorInstrumentation::mediaQueryResultChanged(document);
 
     if (m_deviceMetricsOverridden) {
         m_page->settings().setTextAutosizingEnabled(textAutosizingEnabled);
         m_page->settings().setDeviceScaleAdjustment(fontScaleFactor);
     } else {
         m_page->settings().setTextAutosizingEnabled(m_embedderTextAutosizingEnabled);
         m_page->settings().setDeviceScaleAdjustment(m_embedderFontScaleFactor);
@@ skipping 46 matching lines @@
     String currentMedia = m_state->getString(PageAgentState::pageAgentEmulatedMedia);
     if (media == currentMedia)
         return;
 
     m_state->setString(PageAgentState::pageAgentEmulatedMedia, media);
     Document* document = 0;
     if (m_page->mainFrame())
         document = m_page->mainFrame()->document();
     if (document) {
         document->mediaQueryAffectingValueChanged();
-        document->styleResolverChanged(RecalcStyleImmediately);
+        document->styleResolverChanged(RecalcStyleDeferred);
         document->updateLayout();

[rune, 2014/05/18 10:28:43]

I don't think this updateLayout() call needs to be here. We should be more
explicit about why, when we need an updated layout.

[ojan, 2014/05/18 17:50:39]

My guess is that it's there to trigger this code:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

That said, I don't see why we would need to trigger that code.

     }
 }
 
 bool InspectorPageAgent::applyViewportStyleOverride(StyleResolver* resolver)
 {
     if (!m_deviceMetricsOverridden || !m_emulateViewportEnabled)
         return false;
 
     RefPtrWillBeRawPtr<StyleSheetContents> styleSheet = StyleSheetContents::create(CSSParserContext(UASheetMode, 0));
     styleSheet->parseString(String(viewportAndroidUserAgentStyleSheet, sizeof(viewportAndroidUserAgentStyleSheet)));
@@ skipping 28 matching lines @@
 }
 
 void InspectorPageAgent::setShowViewportSizeOnResize(ErrorString*, bool show, const bool* showGrid)
 {
     m_state->setBoolean(PageAgentState::showSizeOnResize, show);
     m_state->setBoolean(PageAgentState::showGridOnResize, showGrid && *showGrid);
 }
 
 } // namespace WebCore