Implement disambiguation popup

content/common/view_messages.h

Index: content/common/view_messages.h
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index 09b881f61830f325dfe4b4f89a0ecb0151121061..bc18bc82129650f2fd17549d46b1c0b8023020fc 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -1343,6 +1343,11 @@ IPC_MESSAGE_CONTROL1(ViewMsg_TempCrashWithData,
 IPC_MESSAGE_ROUTED1(ViewMsg_SetAccessibilityMode,
                     AccessibilityMode)
 
+// An acknowledge to ViewHostMsg_MultipleTargetsTouched to notify the renderer
+// process to release the magnified image.
+IPC_MESSAGE_ROUTED1(ViewMsg_ReleaseDisambiguationPopupDIB,
+                    TransportDIB::Handle /* DIB handle */)
+
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.
 
@@ -2232,3 +2237,10 @@ IPC_MESSAGE_ROUTED3(ViewHostMsg_PepperPluginHung,
 // Screen was rotated. Dispatched to the onorientationchange javascript API.
 IPC_MESSAGE_ROUTED1(ViewMsg_OrientationChangeEvent,
                     int /* orientation */)
+
+// Notifies that multiple touch targets may have been pressed, and to show
+// the disambiguation popup.
+IPC_MESSAGE_ROUTED3(ViewHostMsg_MultipleTargetsTouched,
+                    gfx::Rect, /* Border of touched targets */
+                    gfx::Size, /* Size of zoomed image */
+                    TransportDIB::Id /* DIB of zoomed image */)