vscode_doc: Add problem matcher for linker errors

Linker errors have a slightly different format as compile errors.
This CL adds a problem matcher for linker errors.

Example: The error
  obj/chrome/browser/chromeos/chromeos/arc_active_directory_enrollment_token_fetcher.o:../../chrome/browser/chromeos/arc/auth/arc_active_directory_enrollment_token_fetcher.cc:vtable for arc::ArcActiveDirectoryEnrollmentTokenFetcher: error: undefined reference to 'non-virtual thunk to arc::ArcActiveDirectoryEnrollmentTokenFetcher::DidFinishNavigation(content::NavigationHandle*)'
is parsed into
  file: 'chrome/browser/chromeos/arc/auth/arc_active_directory_enrollment_token_fetcher.cc'
  severity: 'Error'
  message: 'undefined reference to 'non-virtual thunk to arc::ArcActiveDirectoryEnrollmentTokenFetcher::DidFinishNavigation(content::NavigationHandle*)''

BUG=None
TEST=Regex works

Change-Id: Iaf24212fbfa5ec63ed49668ef0b54d5466309943
Reviewed-on: https://chromium-review.googlesource.com/497847
Commit-Queue: Lutz Justen <[email protected]>
Reviewed-by: jdoerrie <[email protected]>
Cr-Commit-Position: refs/heads/master@{#469679}
diff --git a/docs/vscode.md b/docs/vscode.md
index 100be18..496daca 100644
--- a/docs/vscode.md
+++ b/docs/vscode.md
@@ -235,67 +235,112 @@
     "command": "ninja -C out/Debug -j 2000 chrome",
     "isShellCommand": true,
     "isTestCommand": true,
-    "problemMatcher": {
+    "problemMatcher": [
+    {
       "owner": "cpp",
       "fileLocation": ["relative", "${workspaceRoot}"],
       "pattern": {
         "regexp": "^../../(.*):(\\d+):(\\d+):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
         "file": 1, "line": 2, "column": 3, "severity": 4, "message": 5
       }
-    }
+    },
+    {
+      "owner": "cpp",
+      "fileLocation": ["relative", "${workspaceRoot}"],
+      "pattern": {
+        "regexp": "^../../(.*?):(.*):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
+        "file": 1, "severity": 3, "message": 4
+      }
+    }]
   },
   {
     "taskName": "2-build_chrome_release",
     "command": "ninja -C out/Release -j 2000 chrome",
     "isShellCommand": true,
     "isBuildCommand": true,
-    "problemMatcher": {
+    "problemMatcher": [
+    {
       "owner": "cpp",
       "fileLocation": ["relative", "${workspaceRoot}"],
       "pattern": {
         "regexp": "^../../(.*):(\\d+):(\\d+):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
         "file": 1, "line": 2, "column": 3, "severity": 4, "message": 5
       }
-    }
+    },
+    {
+      "owner": "cpp",
+      "fileLocation": ["relative", "${workspaceRoot}"],
+      "pattern": {
+        "regexp": "^../../(.*?):(.*):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
+        "file": 1, "severity": 3, "message": 4
+      }
+    }]
   },
   {
     "taskName": "3-build_all_debug",
     "command": "ninja -C out/Debug -j 2000",
     "isShellCommand": true,
-    "problemMatcher": {
+    "problemMatcher": [
+    {
       "owner": "cpp",
       "fileLocation": ["relative", "${workspaceRoot}"],
       "pattern": {
         "regexp": "^../../(.*):(\\d+):(\\d+):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
         "file": 1, "line": 2, "column": 3, "severity": 4, "message": 5
       }
-    }
+    },
+    {
+      "owner": "cpp",
+      "fileLocation": ["relative", "${workspaceRoot}"],
+      "pattern": {
+        "regexp": "^../../(.*?):(.*):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
+        "file": 1, "severity": 3, "message": 4
+      }
+    }]
   },
   {
     "taskName": "4-build_all_release",
     "command": "ninja -C out/Release -j 2000",
     "isShellCommand": true,
-    "problemMatcher": {
+    "problemMatcher": [
+    {
       "owner": "cpp",
       "fileLocation": ["relative", "${workspaceRoot}"],
       "pattern": {
         "regexp": "^../../(.*):(\\d+):(\\d+):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
         "file": 1, "line": 2, "column": 3, "severity": 4, "message": 5
       }
-    }
+    },
+    {
+      "owner": "cpp",
+      "fileLocation": ["relative", "${workspaceRoot}"],
+      "pattern": {
+        "regexp": "^../../(.*?):(.*):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
+        "file": 1, "severity": 3, "message": 4
+      }
+    }]
   },
   {
     "taskName": "5-build_test_debug",
     "command": "ninja -C out/Debug -j 2000 unit_tests components_unittests browser_tests",
     "isShellCommand": true,
-    "problemMatcher": {
+    "problemMatcher": [
+    {
       "owner": "cpp",
       "fileLocation": ["relative", "${workspaceRoot}"],
       "pattern": {
         "regexp": "^../../(.*):(\\d+):(\\d+):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
         "file": 1, "line": 2, "column": 3, "severity": 4, "message": 5
       }
-    }
+    },
+    {
+      "owner": "cpp",
+      "fileLocation": ["relative", "${workspaceRoot}"],
+      "pattern": {
+        "regexp": "^../../(.*?):(.*):\\s+(warning|\\w*\\s?error):\\s+(.*)$",
+        "file": 1, "severity": 3, "message": 4
+      }
+    }]
   }]
 }
 ```