[DevTools] Fix crash in Page.reload when there is no visible entry.

content/browser/devtools/protocol/devtools_protocol_browsertest.cc

Index: content/browser/devtools/protocol/devtools_protocol_browsertest.cc
diff --git a/content/browser/devtools/protocol/devtools_protocol_browsertest.cc b/content/browser/devtools/protocol/devtools_protocol_browsertest.cc
index 2a7bf358e6db46c74e0df393f982cfaee1ef25a0..f8cae1af3cc380b587ad2d81ff5008e9cc12a4a7 100644
--- a/content/browser/devtools/protocol/devtools_protocol_browsertest.cc
+++ b/content/browser/devtools/protocol/devtools_protocol_browsertest.cc
@@ -470,4 +470,16 @@ IN_PROC_BROWSER_TEST_F(DevToolsProtocolTest, InspectDuringFrameSwap) {
   EXPECT_TRUE(success);
 }
 
+IN_PROC_BROWSER_TEST_F(DevToolsProtocolTest, ReloadBlankPage) {
+  Shell* window =  Shell::CreateNewWindow(
+      shell()->web_contents()->GetBrowserContext(),
+      GURL("javascript:x=1"),
+      nullptr,
+      gfx::Size());
+  WaitForLoadStop(window->web_contents());
+  Attach();
+  SendCommand("Page.reload", nullptr, false);
+  // Should not crash at this point.
+}
+
 }  // namespace content