Tab Search: Disable context menu

Bug: 1099917
Change-Id: I90dd2b7bf62d6289976c5ae53293773529f0e4a1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2429468Reviewed-by: Thomas Lukaszewicz <tluk@chromium.org>
Commit-Queue: Thomas Lukaszewicz <tluk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810458}

chrome/browser/ui/views/tab_search/tab_search_bubble_view.cc

@@ -35,6 +35,13 @@ class TabSearchWebView : public views::WebView {
     parent_->OnWebViewSizeChanged();
   }
 
+  // content::WebContentsDelegate:
+  bool HandleContextMenu(content::RenderFrameHost* render_frame_host,
+                         const content::ContextMenuParams& params) override {
+    // Ignores context menu.
+    return true;
+  }
+
  private:
   TabSearchBubbleView* parent_;
 };