Add chrome.webstore API methods to allow sites to see progress of installation

chrome/common/extensions/api/webstore.json

Index: chrome/common/extensions/api/webstore.json
diff --git a/chrome/common/extensions/api/webstore.json b/chrome/common/extensions/api/webstore.json
index 31cbd2d01239d79f5abb53706727928da82a6cd2..38d6de3867c759d05a45a0b995e281dc5e979ce9 100644
--- a/chrome/common/extensions/api/webstore.json
+++ b/chrome/common/extensions/api/webstore.json
@@ -6,6 +6,40 @@
   {
     "namespace": "webstore",
     "description": "Use the <code>chrome.webstore</code> API to initiate app and extension installations \"inline\" from your site.",
+    "types": [
+      {
+        "id": "InstallStage",
+        "type": "string",
+        "enum": ["installing", "downloading"],
+        "description": "Enum used to indicate the stage of the installation process. 'downloading' indicates that the necessary files are being downloaded, and 'installing' indicates that the files are downloaded and are being actively installed."
+      }
+    ],  // types
+    "events": [
+      {
+        "name": "onInstallStageChanged",
+        "description": "Fired when an inline installation enters a new InstallStage. In order to receive notifications about this event, listeners must be registered before the inline installation begins.",
+        "type": "function",
+        "parameters": [
+          {
+            "name": "stage",
+            "$ref": "InstallStage",
+            "description": "The InstallStage that just began."
+          }
+        ]
+      },  // onInstallStageChanged
+      {
+        "name": "onDownloadProgress",
+        "description": "Fired periodically with the download progress of an inline install. In order to receive notifications about this event, listeners must be registered before the inline installation begins.",
+        "type": "function",
+        "parameters": [
+          {
+            "name": "percentDownloaded",
+            "type": "number",
+            "description": "The progress of the download, between 0 and 1. 0 indicates no progress; 1.0 indicates complete."
+          }
+        ]
+      }  // onDownloadProgress
+    ],  // events
     "functions": [
       {
         "name": "install",
@@ -39,6 +73,6 @@
           }
         ]
       }  // install
-    ]
+    ]  // functions
   }  // webstore
 ]