Add compile time checks against longs being used in IPC structs on 32 bit Android.

content/browser/renderer_host/text_input_client_message_filter.mm

Index: content/browser/renderer_host/text_input_client_message_filter.mm
diff --git a/content/browser/renderer_host/text_input_client_message_filter.mm b/content/browser/renderer_host/text_input_client_message_filter.mm
index 34e9467826d3134c310a77d75941a4225ac98356..a1efb2e0b3b8dc3a0c2e68d41763b98c25c3e9a6 100644
--- a/content/browser/renderer_host/text_input_client_message_filter.mm
+++ b/content/browser/renderer_host/text_input_client_message_filter.mm
@@ -48,14 +48,17 @@ void TextInputClientMessageFilter::OnGotStringAtPoint(
   service->GetStringAtPointReply(string, NSPointFromCGPoint(point.ToCGPoint()));
 }
 
-void TextInputClientMessageFilter::OnGotCharacterIndexForPoint(size_t index) {
+void TextInputClientMessageFilter::OnGotCharacterIndexForPoint(uint32_t index) {
   TextInputClientMac* service = TextInputClientMac::GetInstance();
   // |index| could be WTF::notFound (-1) and its value is different from
   // NSNotFound so we need to convert it.
-  if (index == static_cast<size_t>(-1)) {
-    index = NSNotFound;
+  size_t char_index;
+  if (index == static_cast<uint32_t>(-1)) {
+    char_index = NSNotFound;
+  } else {
+    char_index = index;
   }
-  service->SetCharacterIndexAndSignal(index);
+  service->SetCharacterIndexAndSignal(char_index);
 }
 
 void TextInputClientMessageFilter::OnGotFirstRectForRange(