Add host-side rate-limiting to desktop resize events.

remoting/webapp/client_session.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * Class handling creation and teardown of a remoting client session.
  *
  * The ClientSession class controls lifetime of the client plugin
  * object and provides the plugin with the functionality it needs to
@@ skipping 236 matching lines @@
 
 /**
  * Set of capabilities for which hasCapability_() can be used to test.
  *
  * @enum {string}
  */
 remoting.ClientSession.Capability = {
   // When enabled this capability causes the client to send its screen
   // resolution to the host once connection has been established. See
   // this.plugin.notifyClientResolution().
-  SEND_INITIAL_RESOLUTION: 'sendInitialResolution'
+  SEND_INITIAL_RESOLUTION: 'sendInitialResolution',
+  RATE_LIMIT_RESIZE_REQUESTS: 'rateLimitResizeRequests'
 };
 
 /**
  * The set of capabilities negotiated between the client and host.
  * @type {Array.<string>}
  * @private
  */
 remoting.ClientSession.prototype.capabilities_ = null;
 
 /**
@@ skipping 615 matching lines @@
   this.updateDimensions();
 
   if (this.notifyClientResolutionTimer_) {
     window.clearTimeout(this.notifyClientResolutionTimer_);
     this.notifyClientResolutionTimer_ = null;
   }
 
   // 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.hasCapability_(
+        remoting.ClientSession.Capability.RATE_LIMIT_RESIZE_REQUESTS)) {
+      kResizeRateLimitMs = 250;
+    }
     this.notifyClientResolutionTimer_ = window.setTimeout(
         this.plugin.notifyClientResolution.bind(this.plugin,
                                                 window.innerWidth,
                                                 window.innerHeight,
                                                 window.devicePixelRatio),
-        1000);
+        kResizeRateLimitMs);
   }
 
   // If bump-scrolling is enabled, adjust the plugin margins to fully utilize
   // the new window area.
   this.scroll_(0, 0);
 };
 
 /**
  * Requests that the host pause or resume video updates.
  *
@@ skipping 318 matching lines @@
       var lateAdjustment = 1 + (now - expected) / timeout;
       if (!that.scroll_(lateAdjustment * dx, lateAdjustment * dy)) {
         that.bumpScrollTimer_ = window.setTimeout(
             function() { repeatScroll(now + timeout); },
             timeout);
       }
     };
     repeatScroll(new Date().getTime());
   }
 };