DevTools: explicitly control support for viewport meta tag so that desktop emulation was possible

Source/web/WebDevToolsAgentImpl.cpp

 /*
  * Copyright (C) 2010-2011 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 180 matching lines @@
 
 WebDevToolsAgentImpl::WebDevToolsAgentImpl(
     WebViewImpl* webViewImpl,
     WebDevToolsAgentClient* client)
     : m_hostId(client->hostIdentifier())
     , m_client(client)
     , m_webViewImpl(webViewImpl)
     , m_attached(false)
     , m_generatingEvent(false)
     , m_deviceMetricsEnabled(false)
+    , m_emulateViewportEnabled(false)
+    , m_originalViewportEnabled(false)
     , m_isOverlayScrollbarsEnabled(false)
-    , m_isCSSViewportEnabled(false)
 {
     ASSERT(m_hostId > 0);
     ClientMessageLoopAdapter::ensureClientMessageLoopCreated(m_client);
 }
 
 WebDevToolsAgentImpl::~WebDevToolsAgentImpl()
 {
     ClientMessageLoopAdapter::inspectedViewClosed(m_webViewImpl);
     if (m_attached)
         WebKit::Platform::current()->currentThread()->removeTaskObserver(this);
@@ skipping 94 matching lines @@
         PlatformMouseEvent mouseEvent = PlatformMouseEventBuilder(page->mainFrame()->view(), *static_cast<const WebMouseEvent*>(&inputEvent));
         return ic->handleMouseEvent(page->mainFrame(), mouseEvent);
     }
     if (WebInputEvent::isTouchEventType(inputEvent.type)) {
         PlatformTouchEvent touchEvent = PlatformTouchEventBuilder(page->mainFrame()->view(), *static_cast<const WebTouchEvent*>(&inputEvent));
         return ic->handleTouchEvent(page->mainFrame(), touchEvent);
     }
     return false;
 }
 
-void WebDevToolsAgentImpl::overrideDeviceMetrics(int width, int height, float deviceScaleFactor, bool fitWindow)
+void WebDevToolsAgentImpl::overrideDeviceMetrics(int width, int height, float deviceScaleFactor, bool emulateViewport, bool fitWindow)
 {
     if (!width && !height) {
         if (m_deviceMetricsEnabled) {
             m_deviceMetricsEnabled = false;
             m_webViewImpl->setBackgroundColorOverride(Color::transparent);
             RuntimeEnabledFeatures::setOverlayScrollbarsEnabled(m_isOverlayScrollbarsEnabled);
-
-            RuntimeEnabledFeatures::setCSSViewportEnabled(m_isCSSViewportEnabled);
-            m_webViewImpl->settings()->setViewportEnabled(false);
-            m_webViewImpl->setIgnoreViewportTagScaleLimits(false);
-            m_webViewImpl->setPageScaleFactorLimits(1, 1);
-
+            disableViewportEmulation();
             m_client->disableDeviceEmulation();
         }
     } else {
         if (!m_deviceMetricsEnabled) {
             m_deviceMetricsEnabled = true;
             m_webViewImpl->setBackgroundColorOverride(Color::darkGray);
             m_isOverlayScrollbarsEnabled = RuntimeEnabledFeatures::overlayScrollbarsEnabled();
             RuntimeEnabledFeatures::setOverlayScrollbarsEnabled(true);
-
-            m_isCSSViewportEnabled = RuntimeEnabledFeatures::cssViewportEnabled();
-            RuntimeEnabledFeatures::setCSSViewportEnabled(true);
-            m_webViewImpl->settings()->setViewportEnabled(true);
-            m_webViewImpl->setIgnoreViewportTagScaleLimits(true);
-            m_webViewImpl->setPageScaleFactorLimits(-1, -1);
         }
+        if (emulateViewport)
+            enableViewportEmulation();
+        else
+            disableViewportEmulation();
         m_client->enableDeviceEmulation(IntSize(width, height), IntRect(0, 0, width, height), deviceScaleFactor, fitWindow);
     }
 }
 
+void WebDevToolsAgentImpl::enableViewportEmulation()
+{
+    if (m_emulateViewportEnabled)
+        return;
+    m_emulateViewportEnabled = true;
+    m_originalViewportEnabled = RuntimeEnabledFeatures::cssViewportEnabled();
+    RuntimeEnabledFeatures::setCSSViewportEnabled(true);
+    m_webViewImpl->settings()->setViewportEnabled(true);
+    m_webViewImpl->setIgnoreViewportTagScaleLimits(true);
+    m_webViewImpl->setPageScaleFactorLimits(-1, -1);
+}
+
+void WebDevToolsAgentImpl::disableViewportEmulation()
+{
+    if (!m_emulateViewportEnabled)
+        return;
+    RuntimeEnabledFeatures::setCSSViewportEnabled(m_originalViewportEnabled);
+    m_webViewImpl->settings()->setViewportEnabled(false);
+    m_webViewImpl->setIgnoreViewportTagScaleLimits(false);
+    m_webViewImpl->setPageScaleFactorLimits(1, 1);
+    m_emulateViewportEnabled = false;
+}
+
 void WebDevToolsAgentImpl::getAllocatedObjects(HashSet<const void*>& set)
 {
     class CountingVisitor : public WebDevToolsAgentClient::AllocatedObjectVisitor {
     public:
         CountingVisitor() : m_totalObjectsCount(0)
         {
         }
 
         virtual bool visitObject(const void* ptr)
         {
@@ skipping 241 matching lines @@
         || commandName == InspectorBackendDispatcher::commandName(InspectorBackendDispatcher::kProfiler_getCPUProfileCmd)
         || commandName == InspectorBackendDispatcher::commandName(InspectorBackendDispatcher::kHeapProfiler_getHeapSnapshotCmd);
 }
 
 void WebDevToolsAgent::processPendingMessages()
 {
     PageScriptDebugServer::shared().runPendingTasks();
 }
 
 } // namespace WebKit