Add functionality for omnibox copied image search suggestion

This CL adds the actual searching for the omnibox suggestion for a
image copied to the user clipboard on iOS (although the tools are there
for other platforms). To do this and prevent reading, manipulating,
and storing the image each time anyone opens the omnibox, I had to add
a way for AutocompleteMatch's to create their post content only after
they have been selected.

Sample timings for doing the image encoding:
Small Image (Wikipedia front page thumbnail):
Resizing image: 0ms
Converting image to bytes: 3ms

Medium Image (iPhone X Screenshot):
Resizing image: 51ms
Converting image to bytes: 14ms

Large Image (Wikipedia List of large images, 50 MB):
Resizing image: 849 ms
Converting image to bytes: 4 ms

Bug: 913958
Change-Id: I84749bf7fd3e584d636faf6b34ade1bf052688dd
Reviewed-on: https://chromium-review.googlesource.com/c/1396030
Reviewed-by: Peter Kasting <[email protected]>
Reviewed-by: Alexei Svitkine <[email protected]>
Reviewed-by: Mark Cogan <[email protected]>
Reviewed-by: Justin Donnelly <[email protected]>
Reviewed-by: Tommy Li <[email protected]>
Reviewed-by: Robert Sesek <[email protected]>
Commit-Queue: Robbie Gibson <[email protected]>
Cr-Commit-Position: refs/heads/master@{#631447}
diff --git a/components/omnibox_strings.grdp b/components/omnibox_strings.grdp
index 661d9db8..a72a746d 100644
--- a/components/omnibox_strings.grdp
+++ b/components/omnibox_strings.grdp
@@ -194,8 +194,14 @@
   <message name="IDS_ACC_AUTOCOMPLETE_BOOKMARK" desc="Text for screenreaders describing a URL from a bookmark.">
     <ph name="LOCATION_TITLE">$2<ex>The Chromium Projects</ex></ph> <ph name="SHORT_URL">$1<ex>www.chromium.org</ex> bookmark</ph>
   </message>
-  <message name="IDS_ACC_AUTOCOMPLETE_CLIPBOARD" desc="Text for screenreaders describing a URL from a clipboard.">
-    <ph name="LOCATION_TITLE">$2<ex>The Chromium Projects</ex></ph> <ph name="SHORT_URL">$1<ex>www.chromium.org</ex> location from clipboard</ph>
+  <message name="IDS_ACC_AUTOCOMPLETE_CLIPBOARD_IMAGE" desc="Text for screenreaders describing an image from a clipboard.">
+    Search for clipboard image
+  </message>
+  <message name="IDS_ACC_AUTOCOMPLETE_CLIPBOARD_TEXT" desc="Text for screenreaders describing text from a clipboard.">
+    Search for clipboard text, <ph name="TEXT">$2<ex>Paris, france</ex></ph>
+  </message>
+  <message name="IDS_ACC_AUTOCOMPLETE_CLIPBOARD_URL" desc="Text for screenreaders describing a URL from a clipboard.">
+    Search for clipboard URL, <ph name="SHORT_URL">$2<ex>www.chromium.org</ex></ph>
   </message>
   <message name="IDS_ACC_SEARCH_ICON" desc="Text for screenreaders describing a search icon image.">
     Search icon