[Android WebView] OnMemoryPressure to drop tile memory

content/public/browser/android/synchronous_compositor.cc

Index: content/public/browser/android/synchronous_compositor.cc
diff --git a/content/public/browser/android/synchronous_compositor.cc b/content/public/browser/android/synchronous_compositor.cc
index 051aa5b34ff13126a440888a1b0d462a78fb9de0..25c4dc4cf3c7b42fa1341b84b9115ed98575aed8 100644
--- a/content/public/browser/android/synchronous_compositor.cc
+++ b/content/public/browser/android/synchronous_compositor.cc
@@ -9,4 +9,15 @@ namespace content {
 SynchronousCompositorMemoryPolicy::SynchronousCompositorMemoryPolicy()
     : bytes_limit(0), num_resources_limit(0) {}
 
+bool SynchronousCompositorMemoryPolicy::operator==(
+    const SynchronousCompositorMemoryPolicy& other) const {
+  return bytes_limit == other.bytes_limit &&
+      num_resources_limit == other.num_resources_limit;
+}
+
+bool SynchronousCompositorMemoryPolicy::operator!=(
+    const SynchronousCompositorMemoryPolicy& other) const {
+  return !(*this == other);
+}
+
 }  // namespace content