Enabled the "search web for image" context menu item when "Yandex"

components/search_engines/template_url.h

Index: components/search_engines/template_url.h
diff --git a/components/search_engines/template_url.h b/components/search_engines/template_url.h
index a5997934c0bf6e94bbc54d812ad27069f455d3c9..e589b7495d3793e722badcf6c73eb90b4a8201ed 100644
--- a/components/search_engines/template_url.h
+++ b/components/search_engines/template_url.h
@@ -181,6 +181,9 @@ class TemplateURLRef {
     // search-by-image frontend.
     std::string image_thumbnail_content;
 
+    // The format of the raw content of an image thumbnail, e.g. "jpeg".

[Peter Kasting, 2015/02/18 21:55:51]

Nit: May want to say something about this needing to be a valid MIME type once
we prepend "image/"?

Optionally, just call this |image_thumbnail_mime_type| and make callers give the
whole type instead of prepending "image/" in template_url.cc.  This is probably
less error-prone.

[Vitaly Baranov, 2015/02/19 17:31:20]

The Yandex.Images service expects a valid image Content-Type at this post
parameter and it seems to be correct to set this type because the format of
binary image data depends on the Chromium internals.

+    std::string image_thumbnail_format;
+
     // When searching for an image, the URL of the original image. Callers
     // should leave this empty for images specified via data: URLs.
     GURL image_url;
@@ -346,8 +349,12 @@ class TemplateURLRef {
 
   // The list of elements to replace.
   typedef std::vector<struct Replacement> Replacements;
-  // Type to store <key, value> pairs for POST URLs.
-  typedef std::pair<std::string, std::string> PostParam;
+  // Type to store parameter for POST URLs.

[Peter Kasting, 2015/02/18 21:55:51]

Nit: How about: "Stores a single parameter for a POST."

[Vitaly Baranov, 2015/02/19 17:31:20]

Done.

+  struct PostParam {

[Peter Kasting, 2015/02/18 21:55:52]

Nit: Move this struct above the two typedefs and put a blank line between it and
them.

[Vitaly Baranov, 2015/02/19 17:31:20]

Done.

+    std::string value_name;

[Peter Kasting, 2015/02/18 21:55:51]

Nit: Why |value_name| instead of just |name|?

[Vitaly Baranov, 2015/02/19 17:31:20]

Renamed. And that was because that name is used in the declaration of function
net::AddMultipartValueForUpload:

NET_EXPORT void AddMultipartValueForUpload(const std::string& value_name,
                                           const std::string& value,
                                           const std::string& mime_boundary,
                                           const std::string& content_type,
                                           std::string* post_data);

+    std::string value;
+    std::string content_type;
+  };
   typedef std::vector<PostParam> PostParams;
 
   // TemplateURLRef internally caches values to make replacement quick. This