Remove DEFINE_WEB_CONTENTS_USER_DATA_KEY in //android_webview.

It is no longer necessary to invoke the DEFINE_WEB_CONTENTS_USER_DATA_KEY
macro to define the global variable from which the key of a
WebContentsUserData is derived. The key is now derived from a static
local variable in WebContentsUserData::UserDataKey().
See https://chromium-review.googlesource.com/c/chromium/src/+/1093015

This CL was uploaded by git cl split.

R=torne@chromium.org

Bug: 589840
Change-Id: I4fbd69c788fc06549d32b4d12199309bbd1bbe1f
Reviewed-on: https://chromium-review.googlesource.com/1150283
Commit-Queue: François Doray <fdoray@chromium.org>
Reviewed-by: Richard Coles <torne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578294}

android_webview/browser/aw_autofill_client.cc

@@ -33,8 +33,6 @@ using base::android::JavaParamRef;
 using base::android::ScopedJavaLocalRef;
 using content::WebContents;
 
-DEFINE_WEB_CONTENTS_USER_DATA_KEY(android_webview::AwAutofillClient);
-
 namespace android_webview {
 
 // Ownership: The native object is created (if autofill enabled) and owned by

android_webview/browser/aw_print_manager.cc

@@ -10,8 +10,6 @@
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_view_host.h"
 
-DEFINE_WEB_CONTENTS_USER_DATA_KEY(android_webview::AwPrintManager);
-
 namespace android_webview {
 
 struct AwPrintManager::FrameDispatchHelper {