Update web-app client to use plugin notifyDeviceResolution API.

remoting/webapp/client_plugin_async.js

Index: remoting/webapp/client_plugin_async.js
diff --git a/remoting/webapp/client_plugin_async.js b/remoting/webapp/client_plugin_async.js
index 9103586833f0129669458a5986cc7485a30ee22a..bdda43331a69d334967aad471c8d37269c704256 100644
--- a/remoting/webapp/client_plugin_async.js
+++ b/remoting/webapp/client_plugin_async.js
@@ -385,18 +385,27 @@ remoting.ClientPluginAsync.prototype.sendClipboardItem =
 };
 
 /**
- * Notifies the host that the client has the specified dimensions.
+ * Notifies the host that the client has the specified size and pixel density.
  *
- * @param {number} width The available client width.
- * @param {number} height The available client height.
+ * @param {number} width The available client width in DIPs.
+ * @param {number} height The available client height in DIPs.
+ * @param {number} device_scale The number of device pixels per DIP.

[Jamie, 2013/02/11 20:32:02]

Does this depend on the version of the plugin? For older versions, we don't send
the dpi, and I'm not sure if the width and height are expressed in DIPs in that
case. Please update the comment to explain the former point (and the latter, if
relevant).

[Wez, 2013/02/11 23:05:33]

See below - if the plugin doesn't support notifyClientResolution then we use
notifyClientDimensions, which just sends the width and height in DIPs.

Under the hood notifyClientResolution adds the "legacy" DIPs-based width &
height.

  */
-remoting.ClientPluginAsync.prototype.notifyClientDimensions =
-    function(width, height) {
-  if (!this.hasFeature(remoting.ClientPlugin.Feature.NOTIFY_CLIENT_DIMENSIONS))
-    return;
-  this.plugin.postMessage(JSON.stringify(
-      { method: 'notifyClientDimensions',
-        data: { width: width, height: height }}));
+remoting.ClientPluginAsync.prototype.notifyClientResolution =
+    function(width, height, device_scale) {
+  if (this.hasFeature(remoting.ClientPlugin.Feature.NOTIFY_CLIENT_RESOLUTION)) {
+    var dpi = device_scale * 96;
+    this.plugin.postMessage(JSON.stringify(
+        { method: 'notifyClientResolution',
+          data: { width: width * device_scale,
+                  height: height * device_scale,
+                  x_dpi: dpi, y_dpi: dpi }}));
+  } else if (this.hasFeature(
+                 remoting.ClientPlugin.Feature.NOTIFY_CLIENT_DIMENSIONS)) {
+    this.plugin.postMessage(JSON.stringify(
+        { method: 'notifyClientDimensions',
+          data: { width: width, height: height }}));
+  }
 };
 
 /**