[DevTools] Allow overriding only the device scale factor.

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 94 matching lines @@
 
 namespace {
 
 KURL urlWithoutFragment(const KURL& url)
 {
     KURL result = url;
     result.removeFragmentIdentifier();
     return result;
 }
 
+bool anyDeviceMetricsOverrideEnabled(int width, int height, double deviceScaleFactor)
+{
+    return width || height || deviceScaleFactor;
+}
+
 }
 
 static bool decodeBuffer(const char* buffer, unsigned size, const String& textEncodingName, String* result)
 {
     if (buffer) {
         WTF::TextEncoding encoding(textEncodingName);
         if (!encoding.isValid())
             encoding = WindowsLatin1Encoding();
         *result = encoding.decode(buffer, size);
         return true;
@@ skipping 291 matching lines @@
     m_deviceMetricsOverridden = false;
 
     setShowPaintRects(0, false);
     setShowDebugBorders(0, false);
     setShowFPSCounter(0, false);
     setEmulatedMedia(0, String());
     setContinuousPaintingEnabled(0, false);
     setShowScrollBottleneckRects(0, false);
     setShowViewportSizeOnResize(0, false, 0);
 
-    if (!deviceMetricsChanged(0, 0, 1, false, false, 1, false))
+    if (!deviceMetricsChanged(0, 0, 0, false, false, 1, false))
         return;
 
     // When disabling the agent, reset the override values if necessary.
-    updateViewMetrics(0, 0, 1, false, false, m_embedderFontScaleFactor, m_embedderTextAutosizingEnabled);
+    updateViewMetrics(0, 0, 0, false, false, m_embedderFontScaleFactor, m_embedderTextAutosizingEnabled);
     m_state->setLong(PageAgentState::pageAgentScreenWidthOverride, 0);
     m_state->setLong(PageAgentState::pageAgentScreenHeightOverride, 0);
-    m_state->setDouble(PageAgentState::pageAgentDeviceScaleFactorOverride, 1);
+    m_state->setDouble(PageAgentState::pageAgentDeviceScaleFactorOverride, 0);
     m_state->setBoolean(PageAgentState::pageAgentEmulateViewport, false);
     m_state->setBoolean(PageAgentState::pageAgentFitWindow, false);
     m_state->setDouble(PageAgentState::fontScaleFactor, 1);
     m_state->setBoolean(PageAgentState::pageAgentTextAutosizingOverride, false);
 }
 
 void InspectorPageAgent::addScriptToEvaluateOnLoad(ErrorString*, const String& source, String* identifier)
 {
     RefPtr<JSONObject> scripts = m_state->getObject(PageAgentState::pageAgentScriptsToEvaluateOnLoad);
     if (!scripts) {
@@ skipping 243 matching lines @@
     if (width < 0 || height < 0 || width > maxDimension || height > maxDimension) {
         *errorString = "Width and height values must be positive, not greater than " + String::number(maxDimension);
         return;
     }
 
     if (!width ^ !height) {
         *errorString = "Both width and height must be either zero or non-zero at once";
         return;
     }
 
-    if (deviceScaleFactor <= 0) {
-        *errorString = "deviceScaleFactor must be positive";
+    if (deviceScaleFactor < 0) {
+        *errorString = "deviceScaleFactor must be non-negative";
         return;
     }
 
     if (fontScaleFactor <= 0) {
         *errorString = "fontScaleFactor must be positive";
         return;
     }
 
     Settings& settings = m_page->settings();
-    if (width && height && !settings.acceleratedCompositingEnabled()) {
+    if (anyDeviceMetricsOverrideEnabled(width, height, deviceScaleFactor) && !settings.acceleratedCompositingEnabled()) {
         if (errorString)
             *errorString = "Compositing mode is not supported";
         return;
     }
 
     if (!deviceMetricsChanged(width, height, deviceScaleFactor, emulateViewport, fitWindow, fontScaleFactor, textAutosizing))
         return;
 
     m_state->setLong(PageAgentState::pageAgentScreenWidthOverride, width);
     m_state->setLong(PageAgentState::pageAgentScreenHeightOverride, height);
@@ skipping 401 matching lines @@
             childrenArray = TypeBuilder::Array<TypeBuilder::Page::FrameResourceTree>::create();
             result->setChildFrames(childrenArray);
         }
         childrenArray->addItem(buildObjectForFrameTree(child));
     }
     return result;
 }
 
 void InspectorPageAgent::updateViewMetrics(int width, int height, double deviceScaleFactor, bool emulateViewport, bool fitWindow, double fontScaleFactor, bool textAutosizingEnabled)
 {
-    if (width && height && !m_page->settings().acceleratedCompositingEnabled())
+    bool enabled = anyDeviceMetricsOverrideEnabled(width, height, deviceScaleFactor);
+    if (enabled && !m_page->settings().acceleratedCompositingEnabled())
         return;
 
-    m_deviceMetricsOverridden = width && height;
+    m_deviceMetricsOverridden = enabled;
     m_emulateViewportEnabled = emulateViewport;
     m_client->overrideDeviceMetrics(width, height, static_cast<float>(deviceScaleFactor), emulateViewport, fitWindow);
 
     Document* document = mainFrame()->document();
     if (document) {
         document->styleResolverChanged(RecalcStyleImmediately);
         document->mediaQueryAffectingValueChanged();
     }
     InspectorInstrumentation::mediaQueryResultChanged(document);
 
@@ skipping 76 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