Bug 801989 part.4 Set InputContext::mNativeIMEContext on Mac r=smichaud

widget/cocoa/nsChildView.mm

@@ -1613,6 +1613,13 @@ nsChildView::GetInputContext()
       mInputContext.mIMEState.mOpen = IMEState::CLOSED;
       break;
   }
+  mInputContext.mNativeIMEContext = [mView inputContext];
+  // If input context isn't available on this widget, we should set |this|
+  // instead of nullptr since nullptr means that the platform has only one
+  // context per process.
+  if (!mInputContext.mNativeIMEContext) {
+    mInputContext.mNativeIMEContext = this;
+  }
   return mInputContext;
 }
 

widget/cocoa/nsCocoaWindow.h

@@ -294,6 +294,16 @@ public:
     }
     NS_IMETHOD_(InputContext) GetInputContext()
     {
+      NSView* view = mWindow ? [mWindow contentView] : nil;
+      if (view) {
+        mInputContext.mNativeIMEContext = [view inputContext];
+      }
+      // If inputContext isn't available on this window, returns this window's
+      // pointer since nullptr means the platform has only one context per
+      // process.
+      if (!mInputContext.mNativeIMEContext) {
+        mInputContext.mNativeIMEContext = this;
+      }
       return mInputContext;
     }
     NS_IMETHOD BeginSecureKeyboardInput();