Mojoify the RequestThumbnailForContextNode IPC message and reply

chrome/browser/ui/android/context_menu_helper.cc

 // Copyright 2013 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.
 
 #include "chrome/browser/ui/android/context_menu_helper.h"
 
 #include <stdint.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
+#include "base/bind_helpers.h"
 #include "chrome/browser/android/download/download_controller_base.h"
 #include "chrome/browser/ui/tab_contents/core_tab_helper.h"
+#include "chrome/common/thumbnail_capturer.mojom.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 #include "content/public/browser/android/content_view_core.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/context_menu_params.h"
 #include "jni/ContextMenuHelper_jni.h"
 #include "jni/ContextMenuParams_jni.h"
+#include "services/service_manager/public/cpp/interface_provider.h"
 #include "third_party/WebKit/public/web/WebContextMenuData.h"
 #include "ui/android/window_android.h"
 #include "ui/gfx/geometry/point.h"
 
 using base::android::ConvertJavaStringToUTF8;
 using base::android::ConvertUTF8ToJavaString;
 using base::android::ConvertUTF16ToJavaString;
 using base::android::JavaParamRef;
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(ContextMenuHelper);
 
 const int kShareImageMaxWidth = 2048;
 const int kShareImageMaxHeight = 2048;
 
 const char kDataReductionProxyPassthroughHeader[] =
     "Chrome-Proxy: pass-through\r\n";
 
 ContextMenuHelper::ContextMenuHelper(content::WebContents* web_contents)
-    : web_contents_(web_contents) {
+    : web_contents_(web_contents), weak_factory_(this) {
   JNIEnv* env = base::android::AttachCurrentThread();
   java_obj_.Reset(
       env,
       Java_ContextMenuHelper_create(env, reinterpret_cast<long>(this)).obj());
   DCHECK(!java_obj_.is_null());
 }
 
 ContextMenuHelper::~ContextMenuHelper() {
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_ContextMenuHelper_destroy(env, java_obj_);
@@ skipping 92 matching lines @@
       render_frame_host, context_menu_params_.src_url);
 }
 
 void ContextMenuHelper::ShareImage(JNIEnv* env,
                                    const JavaParamRef<jobject>& obj) {
   content::RenderFrameHost* render_frame_host =
       content::RenderFrameHost::FromID(render_process_id_, render_frame_id_);
   if (!render_frame_host)
     return;
 
-  CoreTabHelper::FromWebContents(web_contents_)->
-      RequestThumbnailForContextNode(
-          render_frame_host,
-          0,
-          gfx::Size(kShareImageMaxWidth, kShareImageMaxHeight),
-          base::Bind(&ContextMenuHelper::OnShareImage,
-                     base::Unretained(this)));
+  chrome::mojom::ThumbnailCapturerPtr thumbnail_capturer;
+  render_frame_host->GetRemoteInterfaces()->GetInterface(&thumbnail_capturer);
+  // Bind the InterfacePtr into the callback so that it's kept alive until
+  // there's either a connection error or a response.
+  thumbnail_capturer->RequestThumbnailForContextNode(
+      0, gfx::Size(kShareImageMaxWidth, kShareImageMaxHeight),
+      base::Bind(&ContextMenuHelper::OnShareImage, weak_factory_.GetWeakPtr(),
+                 base::Passed(&thumbnail_capturer)));

[tibell, 2017/03/09 02:21:49]

This move is probably undefined behavior since you're calling methods on
thumbnail_capturer after moving. Take a raw pointer to it first and use that for
the call and keep the move as is.

[watk, 2017/03/09 04:01:01]

Discussed offline. Looks like this is guaranteed to work by the standard. The
expression naming the function is sequenced before the arguments are evaluated.
But it relies on the move constructor not changing the address of the underlying
proxy object.

 }
 
-void ContextMenuHelper::OnShareImage(const std::string& thumbnail_data,
-                                     const gfx::Size& original_size) {
+void ContextMenuHelper::OnShareImage(
+    chrome::mojom::ThumbnailCapturerPtr thumbnail_capturer,
+    const std::string& thumbnail_data,
+    const gfx::Size& original_size) {
   content::ContentViewCore* content_view_core =
       content::ContentViewCore::FromWebContents(web_contents_);
   if (!content_view_core)
     return;
 
   base::android::ScopedJavaLocalRef<jobject> jwindow_android(
       content_view_core->GetWindowAndroid()->GetJavaObject());
 
   if (jwindow_android.is_null())
     return;
 
   JNIEnv* env = base::android::AttachCurrentThread();
   base::android::ScopedJavaLocalRef<jbyteArray> j_bytes =
       base::android::ToJavaByteArray(
           env, reinterpret_cast<const uint8_t*>(thumbnail_data.data()),
           thumbnail_data.length());
 
   Java_ContextMenuHelper_onShareImageReceived(env, java_obj_, jwindow_android,
                                               j_bytes);
 }
 
 bool RegisterContextMenuHelper(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }