Listen to didReceiveResponse() to get the response in WebViewPlugin.

This is a partial revert of the WebViewPlugin changes in
https://crrev.com/8489f1bf78c2c6f296e0df6c529751d29e8a0188

BUG=641028

Review-Url: https://codereview.chromium.org/2349443003
Cr-Commit-Position: refs/heads/master@{#419387}

components/plugins/renderer/webview_plugin.cc

@@ -95,23 +95,6 @@ WebViewPlugin::~WebViewPlugin() {
 }
 
 void WebViewPlugin::ReplayReceivedData(WebPlugin* plugin) {
-  const WebURLResponse& response = web_frame_->dataSource()->response();
-  if (!response.isNull()) {
-    plugin->didReceiveResponse(response);
-    size_t total_bytes = 0;
-    for (std::list<std::string>::iterator it = data_.begin(); it != data_.end();
-         ++it) {
-      plugin->didReceiveData(
-          it->c_str(), base::checked_cast<int, size_t>(it->length()));
-      total_bytes += it->length();
-    }
-    UMA_HISTOGRAM_MEMORY_KB(
-        "PluginDocument.Memory",
-        (base::checked_cast<int, size_t>(total_bytes / 1024)));
-    UMA_HISTOGRAM_COUNTS(
-        "PluginDocument.NumChunks",
-        (base::checked_cast<int, size_t>(data_.size())));
-  }
   // We need to transfer the |focused_| to new plugin after it loaded.
   if (focused_) {
     plugin->updateFocus(true, blink::WebFocusTypeNone);

components/plugins/renderer/webview_plugin.h

@@ -108,6 +108,11 @@ class WebViewPlugin : public blink::WebPlugin,
       const blink::WebInputEvent& event,
       blink::WebCursorInfo& cursor_info) override;
 
+  // didReceiveResponse() overrides both WebPlugin and WebFrameClient.
+  // The WebFrameClient variant receives callbacks, but the WebPlugin variant
+  // shouldn't.
+  // TODO(japhet): WebViewPlugin shouldn't be a WebFrameClient, after which
+  // didReceiveResponse() should have a NOTREACHED().
   void didReceiveResponse(const blink::WebURLResponse& response) override {}
   void didReceiveData(const char* data, int data_length) override;
   void didFinishLoading() override;