[android_webview] Use auto-sizing for webviews in wrap content mode.

android_webview/common/render_view_messages.h

Index: android_webview/common/render_view_messages.h
diff --git a/android_webview/common/render_view_messages.h b/android_webview/common/render_view_messages.h
index 96d17589c7120f1176e8afd0f41ab398f9ef2e62..3e82a23ac3508ff7bdb80ca130450840663b2ce6 100644
--- a/android_webview/common/render_view_messages.h
+++ b/android_webview/common/render_view_messages.h
@@ -67,6 +67,12 @@ IPC_MESSAGE_ROUTED0(AwViewMsg_ResetScrollAndScaleState)
 IPC_MESSAGE_ROUTED1(AwViewMsg_SetInitialPageScale,
                     double /* page_scale_factor */)
 
+// Toggles the WebKit WebView autosizing algorthm. See
+// FrameView::autoSizeIfEnabled for the implementation.
+IPC_MESSAGE_ROUTED2(AwViewMsg_SetAutoResizeMode,
+                    bool /* enable */,
+                    int /* width */)
+
 // Sets the base background color for this view.
 IPC_MESSAGE_ROUTED1(AwViewMsg_SetBackgroundColor,
                     SkColor);