GuestView: Lazily push attributes to the browser process on attach

Only push attributes to the browser process on attach that have changed
since create.

This CL also allows partial changes to autosize parameters.

BUG=471402

Review URL: https://codereview.chromium.org/1033373003

Cr-Commit-Position: refs/heads/master@{#322683}

extensions/browser/guest_view/guest_view_base.cc

@@ -785,21 +785,21 @@ double GuestViewBase::GetEmbedderZoomFactor() {
 
 void GuestViewBase::SetUpSizing(const base::DictionaryValue& params) {
   // Read the autosize parameters passed in from the embedder.
-  bool auto_size_enabled = false;
+  bool auto_size_enabled = auto_size_enabled_;
   params.GetBoolean(guestview::kAttributeAutoSize, &auto_size_enabled);
 
-  int max_height = 0;
-  int max_width = 0;
+  int max_height = max_auto_size_.height();
+  int max_width = max_auto_size_.width();
   params.GetInteger(guestview::kAttributeMaxHeight, &max_height);
   params.GetInteger(guestview::kAttributeMaxWidth, &max_width);
 
-  int min_height = 0;
-  int min_width = 0;
+  int min_height = min_auto_size_.height();
+  int min_width = min_auto_size_.width();
   params.GetInteger(guestview::kAttributeMinHeight, &min_height);
   params.GetInteger(guestview::kAttributeMinWidth, &min_width);
 
-  int normal_height = 0;
-  int normal_width = 0;
+  int normal_height = normal_size_.height();
+  int normal_width = normal_size_.width();
   if (is_full_page_plugin()) {
     // The initial size of a full page plugin should be set to fill the
     // owner's visible viewport.

extensions/renderer/resources/guest_view/guest_view_attributes.js

@@ -9,9 +9,10 @@
 
 // Default implementation of a GuestView attribute.
 function Attribute(name, view) {
+  this.dirty = false;
+  this.ignoreMutation = false;
   this.name = name;
   this.view = view;
-  this.ignoreMutation = false;
 
   this.defineProperty();
 }
@@ -21,6 +22,15 @@ Attribute.prototype.getValue = function() {
   return this.view.element.getAttribute(this.name) || '';
 };
 
+// Retrieves and returns the attribute's value if it has been dirtied since
+// the last time this method was called. Returns null otherwise.
+Attribute.prototype.getValueIfDirty = function() {
+  if (!this.dirty)
+    return null;
+  this.dirty = false;
+  return this.getValue();
+};
+
 // Sets the attribute's value.
 Attribute.prototype.setValue = function(value) {
   this.view.element.setAttribute(this.name, value || '');
@@ -51,6 +61,7 @@ Attribute.prototype.maybeHandleMutation = function(oldValue, newValue) {
   if (this.ignoreMutation)
     return;
 
+  this.dirty = true;
   this.handleMutation(oldValue, newValue);
 };
 

extensions/renderer/resources/guest_view/web_view/web_view.js

@@ -55,6 +55,10 @@ WebViewImpl.setupElement = function(proto) {
 
 // Initiates navigation once the <webview> element is attached to the DOM.
 WebViewImpl.prototype.onElementAttached = function() {
+  // Mark all attributes as dirty on attachment.
+  for (var i in this.attributes) {
+    this.attributes[i].dirty = true;
+  }
   for (var i in this.attributes) {
     this.attributes[i].attach();
   }
@@ -63,6 +67,9 @@ WebViewImpl.prototype.onElementAttached = function() {
 // Resets some state upon detaching <webview> element from the DOM.
 WebViewImpl.prototype.onElementDetached = function() {
   this.guest.destroy();
+  for (var i in this.attributes) {
+    this.attributes[i].dirty = false;
+  }
   for (var i in this.attributes) {
     this.attributes[i].detach();
   }
@@ -167,7 +174,9 @@ WebViewImpl.prototype.onAttach = function(storagePartitionId) {
 WebViewImpl.prototype.buildContainerParams = function() {
   var params = { 'userAgentOverride': this.userAgentOverride };
   for (var i in this.attributes) {
-    params[i] = this.attributes[i].getValue();
+    var value = this.attributes[i].getValueIfDirty();
+    if (value)
+      params[i] = value;
   }
   return params;
 };