Temporarily add travis/analyze.sh back for Chrome bot (#5961)

Until https://chromium-review.googlesource.com/c/chromium/tools/build/+/1164636
landed, we'll use this to unblock the Chrome bot.

travis/analyze.sh

+#!/bin/bash
+echo "Analyzing dart:ui library..."
+RESULTS=`dartanalyzer                                                          \
+  --options flutter/analysis_options.yaml                                      \
+  out/host_debug_unopt/gen/sky/bindings/dart_ui/ui.dart                        \
+  2>&1                                                                         \
+  | grep -v "Native functions can only be declared in the SDK and code that is loaded through native extensions" \
+  | grep -Ev "The function '.+' (is not|isn't) used"                           \
+  | grep -Ev "The top level variable '.+' isn't used"                          \
+  | grep -Ev "Undefined name 'main'"                                           \
+  | grep -v "The library 'dart:_internal' is internal"                         \
+  | grep -Ev "Unused import.+ui\.dart"                                         \
+  | grep -Ev "[0-9]+ errors.*found\."                                          \
+  | grep -Ev "Analyzing.+out/host_debug_unopt/gen/sky/bindings/dart_ui/ui\.dart"`
+
+echo "$RESULTS"
+if [ -n "$RESULTS" ]; then
+  echo "Failed."
+  exit 1;
+fi
+
+echo "Analyzing frontend_server..."
+RESULTS=`dartanalyzer                                                          \
+  --packages=flutter/frontend_server/.packages                                 \
+  --options flutter/analysis_options.yaml                                      \
+  flutter/frontend_server                                                      \
+  2>&1                                                                         \
+  | grep -Ev "No issues found!"                                                \
+  | grep -Ev "Analyzing.+frontend_server"`
+echo "$RESULTS"
+if [ -n "$RESULTS" ]; then
+  echo "Failed."
+  exit 1;
+fi
+
+echo "Analyzing flutter_kernel_transformers..."
+RESULTS=`dartanalyzer                                                          \
+  --packages=flutter/flutter_kernel_transformers/.packages                     \
+  --options flutter/analysis_options.yaml                                      \
+  flutter/flutter_kernel_transformers                                          \
+  2>&1                                                                         \
+  | grep -Ev "No issues found!"                                                \
+  | grep -Ev "Analyzing.+flutter_kernel_transformers"`
+echo "$RESULTS"
+if [ -n "$RESULTS" ]; then
+  echo "Failed."
+  exit 1;
+fi
+
+echo "Analyzing tools/licenses..."
+(cd flutter/tools/licenses && pub get)
+RESULTS=`dartanalyzer                                                          \
+  --packages=flutter/tools/licenses/.packages                                  \
+  --options flutter/tools/licenses/analysis_options.yaml                       \
+  flutter/tools/licenses                                                       \
+  2>&1                                                                         \
+  | grep -Ev "No issues found!"                                                \
+  | grep -Ev "Analyzing.+tools/licenses"`
+echo "$RESULTS"
+if [ -n "$RESULTS" ]; then
+  echo "Failed."
+  exit 1;
+fi