Translate viewport related meta tags into @viewport descriptors as suggested by the CSS Device Adap…

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 718fed25218b0d3695173c328ef170524980d2d6..5e5e05734f82fba594d0d06c39659134604a67b4 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -53,6 +53,7 @@
 #include "core/css/CSSSelectorList.h"
 #include "core/css/CSSStyleRule.h"
 #include "core/css/CSSValueList.h"
+#include "core/css/CSSValuePool.h"
 #include "core/css/CSSVariableValue.h"
 #include "core/css/ElementRuleCollector.h"
 #include "core/css/FontFeatureValue.h"
@@ -87,7 +88,9 @@
 #include "core/page/Frame.h"
 #include "core/page/FrameView.h"
 #include "core/page/Page.h"
+#include "core/page/PageGroup.h"
 #include "core/page/Settings.h"
+#include "core/page/UserStyleSheet.h"
 #include "core/platform/graphics/filters/custom/CustomFilterConstants.h"
 #include "core/platform/text/LocaleToScriptMapping.h"
 #include "core/rendering/RenderView.h"
@@ -164,6 +167,13 @@ StyleResolver::StyleResolver(Document* document, bool matchAuthorAndUserStyles)
 
     m_styleTree.clear();
 
+    if (document->isXHTMLMobileProfile()) {
+        Vector<String> whitelist;
+        whitelist.append(document->url());
+        static const char* sheet = "@viewport{-internal-priority:1;width:auto;height:auto;zoom:1;}";
+        document->page()->group().addUserStyleSheet(sheet, KURL(), whitelist, Vector<String>(), InjectInAllFrames, UserStyleAuthorLevel, InjectInExistingDocuments);
+    }
+
     DocumentStyleSheetCollection* styleSheetCollection = document->styleSheetCollection();
     m_ruleSets.initUserStyle(styleSheetCollection, *m_medium, *this);
 
@@ -187,6 +197,7 @@ void StyleResolver::appendAuthorStyleSheets(unsigned firstNew, const Vector<RefP
     unsigned size = styleSheets.size();
     for (unsigned i = firstNew; i < size; ++i) {
         CSSStyleSheet* cssSheet = styleSheets[i].get();
+
         ASSERT(!cssSheet->disabled());
         if (cssSheet->mediaQueries() && !m_medium->eval(cssSheet->mediaQueries(), this))
             continue;
@@ -203,8 +214,7 @@ void StyleResolver::appendAuthorStyleSheets(unsigned firstNew, const Vector<RefP
     if (document()->renderer() && document()->renderer()->style())
         document()->renderer()->style()->font().update(fontSelector());
 
-    if (RuntimeEnabledFeatures::cssViewportEnabled())
-        collectViewportRules();
+    collectViewportRules();
 }
 
 void StyleResolver::resetAuthorStyle()
@@ -934,12 +944,12 @@ PassRefPtr<RenderStyle> StyleResolver::styleForPage(int pageIndex)
 
 void StyleResolver::collectViewportRules()
 {
-    ASSERT(RuntimeEnabledFeatures::cssViewportEnabled());
-
     collectViewportRules(CSSDefaultStyleSheets::defaultStyle);
     if (m_ruleSets.userStyle())
         collectViewportRules(m_ruleSets.userStyle());
 
+    // OK to collect here for viewport meta etc, only the parser doesn't allow addition
+    // of @viewport with the runtime check.
     if (ScopedStyleResolver* scopedResolver = m_styleTree.scopedStyleResolverForDocument())
         scopedResolver->collectViewportRulesTo(this);
 
@@ -948,8 +958,6 @@ void StyleResolver::collectViewportRules()
 
 void StyleResolver::collectViewportRules(RuleSet* rules)
 {
-    ASSERT(RuntimeEnabledFeatures::cssViewportEnabled());
-
     rules->compactRulesIfNeeded();
 
     const Vector<StyleRuleViewport*>& viewportRules = rules->viewportRules();
@@ -1484,7 +1492,8 @@ bool StyleResolver::affectedByViewportChange() const
         if (m_medium->eval(&m_viewportDependentMediaQueryResults[i]->m_expression) != m_viewportDependentMediaQueryResults[i]->m_result)
             return true;
     }
-    return false;
+
+    return m_viewportStyleResolver->affectedByViewportChange();

[Mikhail, 2013/07/19 12:56:21]

This is causing dead loop if having '%' values of viewport width/height
descriptors: m_viewportStyleResolver->affectedByViewportChange() always returns
true in this case -> StyleResolver::affectedByViewportChange() returns true
also.

So have the following loop:
FrameView::performPostLayoutTasks() -> Document::styleResolverChanged() ->
view()->scheduleRelayout() -> FrameView::performPostLayoutTasks().

Document::styleResolverChanged() is invoked in
FrameView::performPostLayoutTasks() on following condition:

if (m_frame->document()->styleResolver()->affectedByViewportChange())

So, one solution could be changing it to:

if (resized && m_frame->document()->styleResolver()->affectedByViewportChange())


but first we need to make sure that it would not bring regressions to orienation
media queries.

 }
 
 void StyleResolver::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const