Support fetching AwContents from a WebContents

This is to allow callbacks coming up from WebContents to find their way back to the java AwContents[Client]


BUG=


Review URL: https://chromiumcodereview.appspot.com/10868095

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@153617 0039d316-1c4b-4281-b951-d872f2087c98

android_webview/native/aw_contents.cc

@@ -9,6 +9,7 @@
 #include "android_webview/native/aw_web_contents_delegate.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
+#include "base/supports_user_data.h"
 #include "content/public/browser/android/content_view_core.h"
 #include "content/public/browser/web_contents.h"
 #include "jni/AwContents_jni.h"
@@ -20,6 +21,31 @@ using content::WebContents;
 
 namespace android_webview {
 
+namespace {
+
+const void* kAwContentsUserDataKey = &kAwContentsUserDataKey;
+
+class AwContentsUserData : public base::SupportsUserData::Data {
+ public:
+  AwContentsUserData(AwContents* ptr) : contents_(ptr) {}
+  AwContents* get() { return contents_; }
+
+ private:
+  AwContents* contents_;
+};
+
+}  // namespace
+
+// static
+AwContents* AwContents::FromWebContents(content::WebContents* web_contents) {
+  if (web_contents) {
+    AwContentsUserData* data = reinterpret_cast<AwContentsUserData*>(
+              web_contents->GetUserData(kAwContentsUserDataKey));
+    if (data) return data->get();
+  }
+  return NULL;
+}
+
 AwContents::AwContents(JNIEnv* env,
                        jobject obj,
                        jobject web_contents_delegate,
@@ -36,9 +62,14 @@ AwContents::AwContents(JNIEnv* env,
   web_contents->SetDelegate(web_contents_delegate_.get());
   web_contents_delegate_->SetJavaScriptDialogCreator(
       dependency_factory->GetJavaScriptDialogCreator());
+  web_contents->SetUserData(kAwContentsUserDataKey,
+                            new AwContentsUserData(this));
 }
 
 AwContents::~AwContents() {
+  content::WebContents* web_contents = contents_container_->GetWebContents();
+  DCHECK(AwContents::FromWebContents(web_contents) == this);
+  web_contents->RemoveUserData(kAwContentsUserDataKey);
 }
 
 jint AwContents::GetWebContents(JNIEnv* env, jobject obj) {

android_webview/native/aw_contents.h

@@ -27,12 +27,16 @@ class AwWebContentsDelegate;
 // level of indirection provided by the AwContentsContainer abstraction.
 class AwContents {
  public:
+  // Returns the AwContents instance associated with |web_contents|, or NULL.
+  static AwContents* FromWebContents(content::WebContents* web_contents);
+
   AwContents(JNIEnv* env,
              jobject obj,
              jobject web_contents_delegate,
              bool private_browsing);
   ~AwContents();
 
+  // Methods called from Java.
   jint GetWebContents(JNIEnv* env, jobject obj);
   void Destroy(JNIEnv* env, jobject obj);