CRD Viewport Management refactor

remoting/webapp/crd/js/desktop_connected_view.js

Index: remoting/webapp/crd/js/desktop_connected_view.js
diff --git a/remoting/webapp/crd/js/desktop_connected_view.js b/remoting/webapp/crd/js/desktop_connected_view.js
index 140607eebf2fd4c44e703e90707f772e52e4ad94..cae7f5fd7766661f4413aa0fb3cc6a1a85a86924 100644
--- a/remoting/webapp/crd/js/desktop_connected_view.js
+++ b/remoting/webapp/crd/js/desktop_connected_view.js
@@ -27,9 +27,7 @@ remoting.enableMouseLock = false;
 /**
  * @param {remoting.ClientSession} session
  * @param {HTMLElement} container
- * @param {string} hostDisplayName A human-readable name for the host.
- * @param {string} hostId The host identifier for Me2Me, or empty for IT2Me.
- *     Mixed into authentication hashes for some authentication methods.
+ * @param {remoting.Host} host
  * @param {remoting.DesktopConnectedView.Mode} mode The mode of this connection.
  * @param {string} defaultRemapKeys The default set of remap keys, to use
  *     when the client doesn't define any.
@@ -37,9 +35,8 @@ remoting.enableMouseLock = false;
  * @constructor
  * @extends {base.EventSourceImpl}
  */
-remoting.DesktopConnectedView = function(session, container, hostDisplayName,
-                                    hostId, mode, defaultRemapKeys,
-                                    onInitialized) {
+remoting.DesktopConnectedView = function(session, container, host, mode,
+                                         defaultRemapKeys, onInitialized) {
   this.session_ = session;
 
   /** @type {HTMLElement} @private */
@@ -49,23 +46,11 @@ remoting.DesktopConnectedView = function(session, container, hostDisplayName,
   this.plugin_ = null;
 
   /** @private */
-  this.hostDisplayName_ = hostDisplayName;
-
-  /** @private */
-  this.hostId_ = hostId;
+  this.host_ = host;
 
   /** @private */
   this.mode_ = mode;
 
-  /** @type {boolean} @private */
-  this.shrinkToFit_ = true;
-
-  /** @type {boolean} @private */
-  this.resizeToClient_ = true;
-
-  /** @type {number} @private */
-  this.desktopScale_ = 1.0;
-
   /** @type {string} @private */
   this.defaultRemapKeys_ = defaultRemapKeys;
 
@@ -86,13 +71,13 @@ remoting.DesktopConnectedView = function(session, container, hostDisplayName,
   /** @private */
   this.callPluginGotFocus_ = this.pluginGotFocus_.bind(this);
 
-  /** @type {number?} @private */
-  this.notifyClientResolutionTimer_ = null;
-
   /** @type {Element} @private */
   this.mouseCursorOverlay_ =
       this.container_.querySelector('.mouse-cursor-overlay');
 
+  /** @private {remoting.DesktopViewport} */
+  this.viewport_ = null;
+
   /** @type {Element} */
   var img = this.mouseCursorOverlay_;
   /** @param {Event} event @private */
@@ -101,29 +86,12 @@ remoting.DesktopConnectedView = function(session, container, hostDisplayName,
     img.style.left = event.x + 'px';
   };
 
-  /** @type {number?} @private */
-  this.bumpScrollTimer_ = null;
-
-  // Bump-scroll test variables. Override to use a fake value for the width
-  // and height of the client plugin so that bump-scrolling can be tested
-  // without relying on the actual size of the host desktop.
-  /** @type {number} @private */
-  this.pluginWidthForBumpScrollTesting = 0;
-  /** @type {number} @private */
-  this.pluginHeightForBumpScrollTesting = 0;
-
   /** @type {remoting.VideoFrameRecorder} @private */
   this.videoFrameRecorder_ = null;
 };
 
 base.extend(remoting.DesktopConnectedView, base.EventSourceImpl);
 
-/** @enum {string} */
-remoting.DesktopConnectedView.Events = {
-  bumpScrollStarted: 'bumpScrollStarted',
-  bumpScrollStopped: 'bumpScrollStopped'
-};
-
 // The mode of this session.
 /** @enum {number} */
 remoting.DesktopConnectedView.Mode = {
@@ -144,7 +112,7 @@ remoting.DesktopConnectedView.KEY_DESKTOP_SCALE = 'desktopScale';
  * @return {string}
  */
 remoting.DesktopConnectedView.prototype.getHostDisplayName = function() {
-  return this.hostDisplayName_;
+  return this.host_.hostName;
 };
 
 /**
@@ -158,33 +126,26 @@ remoting.DesktopConnectedView.prototype.getMode = function() {
  * @return {boolean} True if shrink-to-fit is enabled; false otherwise.
  */
 remoting.DesktopConnectedView.prototype.getShrinkToFit = function() {
-  return this.shrinkToFit_;
+  if (this.viewport_) {
+    return this.viewport_.getShrinkToFit();
+  }
 };
 
 /**
  * @return {boolean} True if resize-to-client is enabled; false otherwise.
  */
 remoting.DesktopConnectedView.prototype.getResizeToClient = function() {
-  return this.resizeToClient_;
+  if (this.viewport_) {
+    return this.viewport_.getResizeToClient();
+  }
 };
 
 /**
  * @return {Element} The element that should host the plugin.
+ * @private
  */
-remoting.DesktopConnectedView.prototype.getPluginContainer = function() {
-  return this.container_.querySelector('.client-plugin-container')
-};
-
-/**
- * @return {{width: number, height: number}} The height of the window's client
- *     area. This differs between apps v1 and apps v2 due to the custom window
- *     borders used by the latter.
- * TODO: make private
- */
-remoting.DesktopConnectedView.prototype.getClientArea_ = function() {
-  return remoting.windowFrame ?
-      remoting.windowFrame.getClientArea() :
-      { 'width': window.innerWidth, 'height': window.innerHeight };
+remoting.DesktopConnectedView.prototype.getPluginContainer_ = function() {
+  return this.container_.querySelector('.client-plugin-container');
 };
 
 /**
@@ -193,10 +154,14 @@ remoting.DesktopConnectedView.prototype.getClientArea_ = function() {
  * TODO: private
  */
 remoting.DesktopConnectedView.prototype.notifyClientResolution_ = function() {
-  var clientArea = this.getClientArea_();
-  this.plugin_.notifyClientResolution(clientArea.width * this.desktopScale_,
-                                      clientArea.height * this.desktopScale_,
-                                      window.devicePixelRatio);
+  if (this.viewport_) {
+    this.viewport_.resizeHostDesktop();
+  }
+};
+
+/** @return {remoting.DesktopViewport} */
+remoting.DesktopConnectedView.prototype.getViewportForTesting = function() {
+  return this.viewport_;
 };
 
 /**
@@ -205,52 +170,18 @@ remoting.DesktopConnectedView.prototype.notifyClientResolution_ = function() {
  * @param {function(string, string):boolean} onExtensionMessage The handler for
  *     protocol extension messages. Returns true if a message is recognized;
  *     false otherwise.
- * @param {Array<string>} requiredCapabilities A list of capabilities
+ * @param {Array.<string>} requiredCapabilities A list of capabilities
  *     required by this application.
  */
 remoting.DesktopConnectedView.prototype.createPluginAndConnect =
     function(onExtensionMessage, requiredCapabilities) {
   this.plugin_ = remoting.ClientPlugin.factory.createPlugin(
-      this.getPluginContainer(),
+      this.getPluginContainer_(),
       onExtensionMessage, requiredCapabilities);
-  remoting.HostSettings.load(this.hostId_,
-                             this.onHostSettingsLoaded_.bind(this));
-};
-
-/**
- * @param {Object<string|boolean|number>} options The current options for the
- *     host, or {} if this client has no saved settings for the host.
- * @private
- */
-remoting.DesktopConnectedView.prototype.onHostSettingsLoaded_ = function(
-    options) {
-  if (remoting.DesktopConnectedView.KEY_REMAP_KEYS in options &&
-      typeof(options[remoting.DesktopConnectedView.KEY_REMAP_KEYS]) ==
-          'string') {
-    this.remapKeys_ = /** @type {string} */
-        (options[remoting.DesktopConnectedView.KEY_REMAP_KEYS]);
-  }
-  if (remoting.DesktopConnectedView.KEY_RESIZE_TO_CLIENT in options &&
-      typeof(options[remoting.DesktopConnectedView.KEY_RESIZE_TO_CLIENT]) ==
-          'boolean') {
-    this.resizeToClient_ = /** @type {boolean} */
-        (options[remoting.DesktopConnectedView.KEY_RESIZE_TO_CLIENT]);
-  }
-  if (remoting.DesktopConnectedView.KEY_SHRINK_TO_FIT in options &&
-      typeof(options[remoting.DesktopConnectedView.KEY_SHRINK_TO_FIT]) ==
-          'boolean') {
-    this.shrinkToFit_ = /** @type {boolean} */
-        (options[remoting.DesktopConnectedView.KEY_SHRINK_TO_FIT]);
-  }
-  if (remoting.DesktopConnectedView.KEY_DESKTOP_SCALE in options &&
-      typeof(options[remoting.DesktopConnectedView.KEY_DESKTOP_SCALE]) ==
-          'number') {
-    this.desktopScale_ = /** @type {number} */
-        (options[remoting.DesktopConnectedView.KEY_DESKTOP_SCALE]);
-  }
-
-  /** @param {boolean} result */
-  this.plugin_.initialize(this.onPluginInitialized_.bind(this));
+  var that = this;
+  this.host_.options().load().then(function(){
+    that.plugin_.initialize(that.onPluginInitialized_.bind(that));
+  });
 };
 
 /**
@@ -293,89 +224,20 @@ remoting.DesktopConnectedView.prototype.onPluginInitialized_ = function(
     this.plugin_.allowMouseLock();
   }
 
-  this.plugin_.setDesktopShapeUpdateHandler(
-      this.onDesktopShapeChanged_.bind(this));
-  this.plugin_.setDesktopSizeUpdateHandler(
-      this.onDesktopSizeChanged_.bind(this));
   this.plugin_.setMouseCursorHandler(this.updateMouseCursorImage_.bind(this));
 
   this.onInitialized_(remoting.Error.NONE, this.plugin_);
 };
 
 /**
- * This is a callback that gets called when the plugin notifies us of a change
- * in the size of the remote desktop.
- *
- * @return {void} Nothing.
- * @private
- */
-remoting.DesktopConnectedView.prototype.onDesktopSizeChanged_ = function() {
-  console.log('desktop size changed: ' +
-              this.plugin_.getDesktopWidth() + 'x' +
-              this.plugin_.getDesktopHeight() +' @ ' +
-              this.plugin_.getDesktopXDpi() + 'x' +
-              this.plugin_.getDesktopYDpi() + ' DPI');
-  this.updateDimensions();
-  this.updateScrollbarVisibility();
-};
-
-/**
- * Sets the non-click-through area of the client in response to notifications
- * from the plugin of desktop shape changes.
- *
- * @param {Array<Array<number>>} rects List of rectangles comprising the
- *     desktop shape.
- * @return {void} Nothing.
- * @private
- */
-remoting.DesktopConnectedView.prototype.onDesktopShapeChanged_ = function(
-    rects) {
-  // Build the list of rects for the input region.
-  var inputRegion = [];
-  for (var i = 0; i < rects.length; ++i) {
-    var rect = {};
-    rect.left = rects[i][0];
-    rect.top = rects[i][1];
-    rect.width = rects[i][2];
-    rect.height = rects[i][3];
-    inputRegion.push(rect);
-  }
-
-  remoting.windowShape.setDesktopRects(inputRegion);
-};
-
-/**
  * This is a callback that gets called when the window is resized.
  *
  * @return {void} Nothing.
  */
 remoting.DesktopConnectedView.prototype.onResize = function() {
-  this.updateDimensions();
-
-  if (this.notifyClientResolutionTimer_) {
-    window.clearTimeout(this.notifyClientResolutionTimer_);
-    this.notifyClientResolutionTimer_ = null;
+  if (this.viewport_) {
+    this.viewport_.onResize();
   }
-
-  // Defer notifying the host of the change until the window stops resizing, to
-  // avoid overloading the control channel with notifications.
-  if (this.resizeToClient_) {
-    var kResizeRateLimitMs = 1000;
-    if (this.session_.hasCapability(
-        remoting.ClientSession.Capability.RATE_LIMIT_RESIZE_REQUESTS)) {
-      kResizeRateLimitMs = 250;
-    }
-    var clientArea = this.getClientArea_();
-    this.notifyClientResolutionTimer_ = window.setTimeout(
-        this.notifyClientResolution_.bind(this),
-        kResizeRateLimitMs);
-  }
-
-  // If bump-scrolling is enabled, adjust the plugin margins to fully utilize
-  // the new window area.
-  this.resetScroll_();
-
-  this.updateScrollbarVisibility();
 };
 
 /**
@@ -435,7 +297,13 @@ remoting.DesktopConnectedView.prototype.updateClientSessionUi_ = function(
     // Stop listening for full-screen events.
     remoting.fullscreen.removeListener(this.callOnFullScreenChanged_);
 
+    base.dispose(this.viewport_);
+    this.viewport_ = null;
   } else {
+    this.viewport_ = new remoting.DesktopViewport(
+        document.getElementById('scroller'),
+        this.plugin_.hostDesktop(),
+        this.host_.options());
     if (remoting.windowFrame) {
       remoting.windowFrame.setDesktopConnectedView(this);
     }
@@ -446,33 +314,16 @@ remoting.DesktopConnectedView.prototype.updateClientSessionUi_ = function(
       remoting.optionsMenu.setDesktopConnectedView(this);
     }
 
-    if (this.resizeToClient_) {
-      this.notifyClientResolution_();
-    }
-
     document.body.classList.add('connected');
     this.container_.addEventListener(
         'mousemove', this.updateMouseCursorPosition_, true);
     // Activate full-screen related UX.
     remoting.fullscreen.addListener(this.callOnFullScreenChanged_);
-    this.onDesktopSizeChanged_();
     this.setFocusHandlers_();
   }
 };
 
 /**
- * @return {{top: number, left:number}} The top-left corner of the plugin.
- */
-remoting.DesktopConnectedView.prototype.getPluginPositionForTesting = function(
-    ) {
-  var style = this.container_.style;
-  return {
-    top: parseFloat(style.marginTop),
-    left: parseFloat(style.marginLeft)
-  };
-};
-
-/**
  * Constrains the focus to the plugin element.
  * @private
  */
@@ -499,51 +350,7 @@ remoting.DesktopConnectedView.prototype.setFocusHandlers_ = function() {
  */
 remoting.DesktopConnectedView.prototype.setScreenMode =
     function(shrinkToFit, resizeToClient) {
-  if (resizeToClient && !this.resizeToClient_) {
-    this.notifyClientResolution_();
-  }
-
-  // If enabling shrink, reset bump-scroll offsets.
-  var needsScrollReset = shrinkToFit && !this.shrinkToFit_;
-
-  this.shrinkToFit_ = shrinkToFit;
-  this.resizeToClient_ = resizeToClient;
-  this.updateScrollbarVisibility();
-
-  if (this.hostId_ != '') {
-    var options = {};
-    options[remoting.DesktopConnectedView.KEY_SHRINK_TO_FIT] =
-        this.shrinkToFit_;
-    options[remoting.DesktopConnectedView.KEY_RESIZE_TO_CLIENT] =
-        this.resizeToClient_;
-    remoting.HostSettings.save(this.hostId_, options);
-  }
-
-  this.updateDimensions();
-  if (needsScrollReset) {
-    this.resetScroll_();
-  }
-};
-
-/**
- * Sets and stores the scale factor to apply to host sizing requests.
- * The desktopScale applies to the dimensions reported to the host, not
- * to the client DPI reported to it.
- *
- * @param {number} desktopScale Scale factor to apply.
- */
-remoting.DesktopConnectedView.prototype.setDesktopScale = function(
-    desktopScale) {
-  this.desktopScale_ = desktopScale;
-
-  // onResize() will update the plugin size and scrollbars for the new
-  // scaled plugin dimensions, and send a client resolution notification.
-  this.onResize();
-
-  // Save the new desktop scale setting.
-  var options = {};
-  options[remoting.DesktopConnectedView.KEY_DESKTOP_SCALE] = this.desktopScale_;
-  remoting.HostSettings.save(this.hostId_, options);
+  this.viewport_.setScreenMode(shrinkToFit, resizeToClient);
 };
 
 /**
@@ -556,7 +363,9 @@ remoting.DesktopConnectedView.prototype.setDesktopScale = function(
  */
 remoting.DesktopConnectedView.prototype.onFullScreenChanged_ = function (
     fullscreen) {
-  this.enableBumpScroll_(fullscreen);
+  if (this.viewport_) {
+    this.viewport_.enableBumpScroll(fullscreen);
+  }
 };
 
 /**
@@ -599,342 +408,6 @@ remoting.DesktopConnectedView.prototype.updateMouseCursorImage_ =
 };
 
 /**
- * Enable or disable bump-scrolling. When disabling bump scrolling, also reset
- * the scroll offsets to (0, 0).
- * @param {boolean=} enable True to enable bump-scrolling, false to disable it.
- * @private
- */
-remoting.DesktopConnectedView.prototype.enableBumpScroll_ = function(enable) {
-  var element = /** @type{HTMLElement} */ (document.documentElement);
-  if (enable) {
-    /** @type {null|function(Event):void} */
-    this.onMouseMoveRef_ = this.onMouseMove_.bind(this);
-    element.addEventListener('mousemove', this.onMouseMoveRef_, false);
-  } else {
-    element.removeEventListener('mousemove', this.onMouseMoveRef_, false);
-    this.onMouseMoveRef_ = null;
-    this.resetScroll_();
-  }
-};
-
-remoting.DesktopConnectedView.prototype.resetScroll_ = function() {
-  this.container_.style.marginTop = '0px';
-  this.container_.style.marginLeft = '0px';
-};
-
-/**
- * @param {Event} event The mouse event.
- * @private
- */
-remoting.DesktopConnectedView.prototype.onMouseMove_ = function(event) {
-  if (this.bumpScrollTimer_) {
-    window.clearTimeout(this.bumpScrollTimer_);
-    this.bumpScrollTimer_ = null;
-  }
-
-  /**
-   * Compute the scroll speed based on how close the mouse is to the edge.
-   * @param {number} mousePos The mouse x- or y-coordinate
-   * @param {number} size The width or height of the content area.
-   * @return {number} The scroll delta, in pixels.
-   */
-  var computeDelta = function(mousePos, size) {
-    var threshold = 10;
-    if (mousePos >= size - threshold) {
-      return 1 + 5 * (mousePos - (size - threshold)) / threshold;
-    } else if (mousePos <= threshold) {
-      return -1 - 5 * (threshold - mousePos) / threshold;
-    }
-    return 0;
-  };
-
-  var clientArea = this.getClientArea_();
-  var dx = computeDelta(event.x, clientArea.width);
-  var dy = computeDelta(event.y, clientArea.height);
-
-  if (dx != 0 || dy != 0) {
-    this.raiseEvent(remoting.DesktopConnectedView.Events.bumpScrollStarted);
-    /** @type {remoting.DesktopConnectedView} */
-    var that = this;
-    /**
-     * Scroll the view, and schedule a timer to do so again unless we've hit
-     * the edges of the screen. This timer is cancelled when the mouse moves.
-     * @param {number} expected The time at which we expect to be called.
-     */
-    var repeatScroll = function(expected) {
-      /** @type {number} */
-      var now = new Date().getTime();
-      /** @type {number} */
-      var timeout = 10;
-      var lateAdjustment = 1 + (now - expected) / timeout;
-      if (that.scroll_(lateAdjustment * dx, lateAdjustment * dy)) {
-        that.raiseEvent(remoting.DesktopConnectedView.Events.bumpScrollStopped);
-      } else {
-        that.bumpScrollTimer_ = window.setTimeout(
-            function() { repeatScroll(now + timeout); },
-            timeout);
-      }
-    };
-    repeatScroll(new Date().getTime());
-  }
-};
-
-/**
- * Scroll the client plugin by the specified amount, keeping it visible.
- * Note that this is only used in content full-screen mode (not windowed or
- * browser full-screen modes), where window.scrollBy and the scrollTop and
- * scrollLeft properties don't work.
- * @param {number} dx The amount by which to scroll horizontally. Positive to
- *     scroll right; negative to scroll left.
- * @param {number} dy The amount by which to scroll vertically. Positive to
- *     scroll down; negative to scroll up.
- * @return {boolean} True if the requested scroll had no effect because both
- *     vertical and horizontal edges of the screen have been reached.
- * @private
- */
-remoting.DesktopConnectedView.prototype.scroll_ = function(dx, dy) {
-  /**
-   * Helper function for x- and y-scrolling
-   * @param {number|string} curr The current margin, eg. "10px".
-   * @param {number} delta The requested scroll amount.
-   * @param {number} windowBound The size of the window, in pixels.
-   * @param {number} pluginBound The size of the plugin, in pixels.
-   * @param {{stop: boolean}} stop Reference parameter used to indicate when
-   *     the scroll has reached one of the edges and can be stopped in that
-   *     direction.
-   * @return {string} The new margin value.
-   */
-  var adjustMargin = function(curr, delta, windowBound, pluginBound, stop) {
-    var minMargin = Math.min(0, windowBound - pluginBound);
-    var result = (curr ? parseFloat(curr) : 0) - delta;
-    result = Math.min(0, Math.max(minMargin, result));
-    stop.stop = (result == 0 || result == minMargin);
-    return result + 'px';
-  };
-
-  var plugin = this.plugin_.element();
-  var style = this.container_.style;
-
-  var stopX = { stop: false };
-  var clientArea = this.getClientArea_();
-  style.marginLeft = adjustMargin(style.marginLeft, dx, clientArea.width,
-      this.pluginWidthForBumpScrollTesting || plugin.clientWidth, stopX);
-
-  var stopY = { stop: false };
-  style.marginTop = adjustMargin(
-      style.marginTop, dy, clientArea.height,
-      this.pluginHeightForBumpScrollTesting || plugin.clientHeight, stopY);
-  return stopX.stop && stopY.stop;
-};
-
-/**
- * Refreshes the plugin's dimensions, taking into account the sizes of the
- * remote desktop and client window, and the current scale-to-fit setting.
- *
- * @return {void} Nothing.
- */
-remoting.DesktopConnectedView.prototype.updateDimensions = function() {
-  if (this.plugin_.getDesktopWidth() == 0 ||
-      this.plugin_.getDesktopHeight() == 0) {
-    return;
-  }
-
-  var desktopSize = { width: this.plugin_.getDesktopWidth(),
-                      height: this.plugin_.getDesktopHeight() };
-  var desktopDpi = { x: this.plugin_.getDesktopXDpi(),
-                     y: this.plugin_.getDesktopYDpi() };
-  var newSize = remoting.DesktopConnectedView.choosePluginSize(
-      this.getClientArea_(), window.devicePixelRatio,
-      desktopSize, desktopDpi, this.desktopScale_,
-      remoting.fullscreen.isActive(), this.shrinkToFit_);
-
-  // Resize the plugin if necessary.
-  console.log('plugin dimensions:' + newSize.width + 'x' + newSize.height);
-  this.plugin_.element().style.width = newSize.width + 'px';
-  this.plugin_.element().style.height = newSize.height + 'px';
-
-  // When we receive the first plugin dimensions from the host, we know that
-  // remote host has started.
-  remoting.app.onVideoStreamingStarted();
-}
-
-/**
- * Helper function accepting client and host dimensions, and returning a chosen
- * size for the plugin element, in DIPs.
- *
- * @param {{width: number, height: number}} clientSizeDips Available client
- *     dimensions, in DIPs.
- * @param {number} clientPixelRatio Number of physical pixels per client DIP.
- * @param {{width: number, height: number}} desktopSize Size of the host desktop
- *     in physical pixels.
- * @param {{x: number, y: number}} desktopDpi DPI of the host desktop in both
- *     dimensions.
- * @param {number} desktopScale The scale factor configured for the host.
- * @param {boolean} isFullscreen True if full-screen mode is active.
- * @param {boolean} shrinkToFit True if shrink-to-fit should be applied.
- * @return {{width: number, height: number}} Chosen plugin dimensions, in DIPs.
- */
-remoting.DesktopConnectedView.choosePluginSize = function(
-    clientSizeDips, clientPixelRatio, desktopSize, desktopDpi, desktopScale,
-    isFullscreen, shrinkToFit) {
-  base.debug.assert(clientSizeDips.width > 0);
-  base.debug.assert(clientSizeDips.height > 0);
-  base.debug.assert(clientPixelRatio >= 1.0);
-  base.debug.assert(desktopSize.width > 0);
-  base.debug.assert(desktopSize.height > 0);
-  base.debug.assert(desktopDpi.x > 0);
-  base.debug.assert(desktopDpi.y > 0);
-  base.debug.assert(desktopScale > 0);
-
-  // We have the following goals in sizing the desktop display at the client:
-  //  1. Avoid losing detail by down-scaling beyond 1:1 host:device pixels.
-  //  2. Avoid up-scaling if that will cause the client to need scrollbars.
-  //  3. Avoid introducing blurriness with non-integer up-scaling factors.
-  //  4. Avoid having huge "letterboxes" around the desktop, if it's really
-  //     small.
-  //  5. Compensate for mismatched DPIs, so that the behaviour of features like
-  //     shrink-to-fit matches their "natural" rather than their pixel size.
-  //     e.g. with shrink-to-fit active a 1024x768 low-DPI host on a 640x480
-  //     high-DPI client will be up-scaled to 1280x960, rather than displayed
-  //     at 1:1 host:physical client pixels.
-  //
-  // To determine the ideal size we follow a four-stage process:
-  //  1. Determine the "natural" size at which to display the desktop.
-  //    a. Initially assume 1:1 mapping of desktop to client device pixels.
-  //    b. If host DPI is less than the client's then up-scale accordingly.
-  //    c. If desktopScale is configured for the host then allow that to
-  //       reduce the amount of up-scaling from (b). e.g. if the client:host
-  //       DPIs are 2:1 then a desktopScale of 1.5 would reduce the up-scale
-  //       to 4:3, while a desktopScale of 3.0 would result in no up-scaling.
-  //  2. If the natural size of the desktop is smaller than the client device
-  //     then apply up-scaling by an integer scale factor to avoid excessive
-  //     letterboxing.
-  //  3. If shrink-to-fit is configured then:
-  //     a. If the natural size exceeds the client size then apply down-scaling
-  //        by an arbitrary scale factor.
-  //     b. If we're in full-screen mode and the client & host aspect-ratios
-  //        are radically different (e.g. the host is actually multi-monitor)
-  //        then shrink-to-fit to the shorter dimension, rather than leaving
-  //        huge letterboxes; the user can then bump-scroll around the desktop.
-  //  4. If the overall scale factor is fractionally over an integer factor
-  //     then reduce it to that integer factor, to avoid blurring.
-
-  // All calculations are performed in device pixels.
-  var clientWidth = clientSizeDips.width * clientPixelRatio;
-  var clientHeight = clientSizeDips.height * clientPixelRatio;
-
-  // 1. Determine a "natural" size at which to display the desktop.
-  var scale = 1.0;
-
-  // Determine the effective host device pixel ratio.
-  // Note that we round up or down to the closest integer pixel ratio.
-  var hostPixelRatioX = Math.round(desktopDpi.x / 96);
-  var hostPixelRatioY = Math.round(desktopDpi.y / 96);
-  var hostPixelRatio = Math.min(hostPixelRatioX, hostPixelRatioY);
-
-  // Allow up-scaling to account for DPI.
-  scale = Math.max(scale, clientPixelRatio / hostPixelRatio);
-
-  // Allow some or all of the up-scaling to be cancelled by the desktopScale.
-  if (desktopScale > 1.0) {
-    scale = Math.max(1.0, scale / desktopScale);
-  }
-
-  // 2. If the host is still much smaller than the client, then up-scale to
-  //    avoid wasting space, but only by an integer factor, to avoid blurring.
-  if (desktopSize.width * scale <= clientWidth &&
-      desktopSize.height * scale <= clientHeight) {
-    var scaleX = Math.floor(clientWidth / desktopSize.width);
-    var scaleY = Math.floor(clientHeight / desktopSize.height);
-    scale = Math.min(scaleX, scaleY);
-    base.debug.assert(scale >= 1.0);
-  }
-
-  // 3. Apply shrink-to-fit, if configured.
-  if (shrinkToFit) {
-    var scaleFitWidth = Math.min(scale, clientWidth / desktopSize.width);
-    var scaleFitHeight = Math.min(scale, clientHeight / desktopSize.height);
-    scale = Math.min(scaleFitHeight, scaleFitWidth);
-
-    // If we're running full-screen then try to handle common side-by-side
-    // multi-monitor combinations more intelligently.
-    if (isFullscreen) {
-      // If the host has two monitors each the same size as the client then
-      // scale-to-fit will have the desktop occupy only 50% of the client area,
-      // in which case it would be preferable to down-scale less and let the
-      // user bump-scroll around ("scale-and-pan").
-      // Triggering scale-and-pan if less than 65% of the client area would be
-      // used adds enough fuzz to cope with e.g. 1280x800 client connecting to
-      // a (2x1280)x1024 host nicely.
-      // Note that we don't need to account for scrollbars while fullscreen.
-      if (scale <= scaleFitHeight * 0.65) {
-        scale = scaleFitHeight;
-      }
-      if (scale <= scaleFitWidth * 0.65) {
-        scale = scaleFitWidth;
-      }
-    }
-  }
-
-  // 4. Avoid blurring for close-to-integer up-scaling factors.
-  if (scale > 1.0) {
-    var scaleBlurriness = scale / Math.floor(scale);
-    if (scaleBlurriness < 1.1) {
-      scale = Math.floor(scale);
-    }
-  }
-
-  // Return the necessary plugin dimensions in DIPs.
-  scale = scale / clientPixelRatio;
-  var pluginWidth = Math.round(desktopSize.width * scale);
-  var pluginHeight = Math.round(desktopSize.height * scale);
-  return { width: pluginWidth, height: pluginHeight };
-}
-
-/**
- * Called when the window or desktop size or the scaling settings change,
- * to set the scroll-bar visibility.
- *
- * TODO(jamiewalch): crbug.com/252796: Remove this once crbug.com/240772 is
- * fixed.
- */
-remoting.DesktopConnectedView.prototype.updateScrollbarVisibility = function() {
-  var scroller = document.getElementById('scroller');
-  if (!scroller) {
-    return;
-  }
-
-  var needsVerticalScroll = false;
-  var needsHorizontalScroll = false;
-  if (!this.shrinkToFit_) {
-    // Determine whether or not horizontal or vertical scrollbars are
-    // required, taking into account their width.
-    var clientArea = this.getClientArea_();
-    needsVerticalScroll = clientArea.height < this.plugin_.getDesktopHeight();
-    needsHorizontalScroll = clientArea.width < this.plugin_.getDesktopWidth();
-    var kScrollBarWidth = 16;
-    if (needsHorizontalScroll && !needsVerticalScroll) {
-      needsVerticalScroll =
-          clientArea.height - kScrollBarWidth < this.plugin_.getDesktopHeight();
-    } else if (!needsHorizontalScroll && needsVerticalScroll) {
-      needsHorizontalScroll =
-          clientArea.width - kScrollBarWidth < this.plugin_.getDesktopWidth();
-    }
-  }
-
-  if (needsHorizontalScroll) {
-    scroller.classList.remove('no-horizontal-scroll');
-  } else {
-    scroller.classList.add('no-horizontal-scroll');
-  }
-  if (needsVerticalScroll) {
-    scroller.classList.remove('no-vertical-scroll');
-  } else {
-    scroller.classList.add('no-vertical-scroll');
-  }
-};
-
-/**
  * Sets and stores the key remapping setting for the current host.
  *
  * @param {string} remappings Comma separated list of key remappings.
@@ -946,9 +419,8 @@ remoting.DesktopConnectedView.prototype.setRemapKeys = function(remappings) {
   this.applyRemapKeys_(true);
 
   // Save the new remapping setting.
-  var options = {};
-  options[remoting.DesktopConnectedView.KEY_REMAP_KEYS] = this.remapKeys_;
-  remoting.HostSettings.save(this.hostId_, options);
+  this.host_.options().remapKeys = this.remapKeys_;
+  this.host_.options().save();
 };
 
 /**